Merging upstream version 1.67.1+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

37 files changed, 1354 insertions, 79 deletions

diff --git a/src/ci/docker/host-aarch64/aarch64-gnu/Dockerfile b/src/ci/docker/host-aarch64/aarch64-gnu/Dockerfile
index e54d0eafb..699938c37 100644
--- a/src/ci/docker/host-aarch64/aarch64-gnu/Dockerfile
+++ b/src/ci/docker/host-aarch64/aarch64-gnu/Dockerfile
@@ -14,7 +14,8 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-ins
   gdb \
   libssl-dev \
   pkg-config \
-  xz-utils
+  xz-utils \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/host-x86_64/armhf-gnu/Dockerfile b/src/ci/docker/host-x86_64/armhf-gnu/Dockerfile
index 69f88e495..57e63cd39 100644
--- a/src/ci/docker/host-x86_64/armhf-gnu/Dockerfile
+++ b/src/ci/docker/host-x86_64/armhf-gnu/Dockerfile
@@ -9,7 +9,7 @@ RUN apt-get update -y && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-
       curl \
       file \
       g++ \
-      gcc-arm-linux-gnueabihf \
+      g++-arm-linux-gnueabihf \
       git \
       libc6-dev \
       libc6-dev-armhf-cross \
diff --git a/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile b/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile
index 637b5fa22..5ddd3f180 100644
--- a/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile
+++ b/src/ci/docker/host-x86_64/disabled/dist-x86_64-haiku/Dockerfile
@@ -47,6 +47,4 @@ ENV RUST_CONFIGURE_ARGS --disable-jemalloc \
   --set=$TARGET.cc=x86_64-unknown-haiku-gcc \
   --set=$TARGET.cxx=x86_64-unknown-haiku-g++ \
   --set=$TARGET.llvm-config=/bin/llvm-config-haiku
-ENV EXTERNAL_LLVM 1
-
 ENV SCRIPT python3 ../x.py dist --host=$HOST --target=$HOST
diff --git a/src/ci/docker/host-x86_64/dist-i686-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-i686-linux/Dockerfile
index cd86d9fb5..ea4a2a242 100644
--- a/src/ci/docker/host-x86_64/dist-i686-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-i686-linux/Dockerfile
@@ -32,7 +32,8 @@ RUN yum upgrade -y && \
       wget \
       xz \
       zlib-devel.i686 \
-      zlib-devel.x86_64
+      zlib-devel.x86_64 \
+      && yum clean all
 
 RUN mkdir -p /rustroot/bin && ln -s /usr/bin/cmake3 /rustroot/bin/cmake
 
diff --git a/src/ci/docker/host-x86_64/dist-powerpc64le-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-powerpc64le-linux/Dockerfile
index 9a290edd5..6b7b32a8b 100644
--- a/src/ci/docker/host-x86_64/dist-powerpc64le-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-powerpc64le-linux/Dockerfile
@@ -24,5 +24,5 @@ ENV \
 
 ENV HOSTS=powerpc64le-unknown-linux-gnu
 
-ENV RUST_CONFIGURE_ARGS --enable-extended --disable-docs
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-profiler --disable-docs
 ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS
diff --git a/src/ci/docker/host-x86_64/dist-riscv64-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-riscv64-linux/Dockerfile
index 88b8c7ea3..397f9538b 100644
--- a/src/ci/docker/host-x86_64/dist-riscv64-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-riscv64-linux/Dockerfile
@@ -27,5 +27,5 @@ ENV CC_riscv64gc_unknown_linux_gnu=riscv64-unknown-linux-gnu-gcc \
 
 ENV HOSTS=riscv64gc-unknown-linux-gnu
 
-ENV RUST_CONFIGURE_ARGS --enable-extended --disable-docs
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-profiler --disable-docs
 ENV SCRIPT python3 ../x.py dist --target $HOSTS --host $HOSTS
diff --git a/src/ci/docker/host-x86_64/dist-s390x-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-s390x-linux/Dockerfile
index 7d77fdd30..43a449b3a 100644
--- a/src/ci/docker/host-x86_64/dist-s390x-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-s390x-linux/Dockerfile
@@ -28,5 +28,5 @@ ENV \
 
 ENV HOSTS=s390x-unknown-linux-gnu
 
-ENV RUST_CONFIGURE_ARGS --enable-extended --enable-lld --disable-docs
+ENV RUST_CONFIGURE_ARGS --enable-extended --enable-lld --enable-profiler --disable-docs
 ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS
diff --git a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
index 8250ec0c3..93ef7dfcb 100644
--- a/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-various-2/Dockerfile
@@ -61,6 +61,12 @@ ENV \
     AR_i686_unknown_freebsd=i686-unknown-freebsd12-ar \
     CC_i686_unknown_freebsd=i686-unknown-freebsd12-clang \
     CXX_i686_unknown_freebsd=i686-unknown-freebsd12-clang++ \
+    CC_aarch64_unknown_uefi=clang-11 \
+    CXX_aarch64_unknown_uefi=clang++-11 \
+    CC_i686_unknown_uefi=clang-11 \
+    CXX_i686_unknown_uefi=clang++-11 \
+    CC_x86_64_unknown_uefi=clang-11 \
+    CXX_x86_64_unknown_uefi=clang++-11 \
     CC=gcc-8 \
     CXX=g++-8
 
@@ -118,6 +124,9 @@ ENV TARGETS=$TARGETS,armv7-unknown-linux-gnueabi
 ENV TARGETS=$TARGETS,armv7-unknown-linux-musleabi
 ENV TARGETS=$TARGETS,i686-unknown-freebsd
 ENV TARGETS=$TARGETS,x86_64-unknown-none
+ENV TARGETS=$TARGETS,aarch64-unknown-uefi
+ENV TARGETS=$TARGETS,i686-unknown-uefi
+ENV TARGETS=$TARGETS,x86_64-unknown-uefi
 
 # As per https://bugs.launchpad.net/ubuntu/+source/gcc-defaults/+bug/1300211
 # we need asm in the search path for gcc-8 (for gnux32) but not in the search path of the
@@ -129,6 +138,4 @@ ENV RUST_CONFIGURE_ARGS --enable-extended --enable-lld --disable-docs \
   --set target.wasm32-wasi.wasi-root=/wasm32-wasi \
   --musl-root-armv7=/musl-armv7
 
-ENV EXTERNAL_LLVM 1
-
 ENV SCRIPT python3 ../x.py dist --host='' --target $TARGETS
diff --git a/src/ci/docker/host-x86_64/dist-various-2/build-wasi-toolchain.sh b/src/ci/docker/host-x86_64/dist-various-2/build-wasi-toolchain.sh
index 36c94458d..67cee0148 100755
--- a/src/ci/docker/host-x86_64/dist-various-2/build-wasi-toolchain.sh
+++ b/src/ci/docker/host-x86_64/dist-various-2/build-wasi-toolchain.sh
@@ -2,15 +2,15 @@
 
 set -ex
 
-# Originally from https://github.com/llvm/llvm-project/releases/download/llvmorg-14.0.0/clang+llvm-14.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz
-curl https://ci-mirrors.rust-lang.org/rustc/2022-05-10-clang%2Bllvm-14.0.0-x86_64-linux-gnu-ubuntu-18.04.tar.xz | \
+# Originally from https://github.com/llvm/llvm-project/releases/download/llvmorg-15.0.6/clang+llvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04.tar.xz
+curl https://ci-mirrors.rust-lang.org/rustc/2022-12-06-clang%2Bllvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04.tar.xz | \
   tar xJf -
-bin="$PWD/clang+llvm-14.0.0-x86_64-linux-gnu-ubuntu-18.04/bin"
+bin="$PWD/clang+llvm-15.0.6-x86_64-linux-gnu-ubuntu-18.04/bin"
 
 git clone https://github.com/WebAssembly/wasi-libc
 
 cd wasi-libc
-git reset --hard 9886d3d6200fcc3726329966860fc058707406cd
+git reset --hard 8b7148f69ae241a2749b3defe4606da8143b72e0
 make -j$(nproc) \
     CC="$bin/clang" \
     NM="$bin/llvm-nm" \
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
index f9b1fa895..377d4a9ce 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-freebsd/Dockerfile
@@ -15,7 +15,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   xz-utils \
   wget \
   libssl-dev \
-  pkg-config
+  pkg-config \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/freebsd-toolchain.sh /tmp/
 RUN /tmp/freebsd-toolchain.sh x86_64
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-illumos/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-illumos/Dockerfile
index c2e44ead5..4e46bdee5 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-illumos/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-illumos/Dockerfile
@@ -11,7 +11,8 @@ RUN apt-get update && \
     apt-get install -y --no-install-recommends \
       libgmp-dev \
       libmpfr-dev \
-      libmpc-dev
+      libmpc-dev \
+      && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/illumos-toolchain.sh /tmp/
 
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
index 423aba06c..6bdc88e18 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile
@@ -32,7 +32,8 @@ RUN yum upgrade -y && \
       wget \
       xz \
       zlib-devel.i686 \
-      zlib-devel.x86_64
+      zlib-devel.x86_64 \
+      && yum clean all
 
 RUN mkdir -p /rustroot/bin && ln -s /usr/bin/cmake3 /rustroot/bin/cmake
 
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-musl/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-musl/Dockerfile
index 51645a818..13eaf7fce 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-musl/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-musl/Dockerfile
@@ -16,7 +16,8 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-ins
   gdb \
   patch \
   libssl-dev \
-  pkg-config
+  pkg-config \
+  && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /build/
 
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-netbsd/Dockerfile b/src/ci/docker/host-x86_64/dist-x86_64-netbsd/Dockerfile
index fed4be4c3..d03c36454 100644
--- a/src/ci/docker/host-x86_64/dist-x86_64-netbsd/Dockerfile
+++ b/src/ci/docker/host-x86_64/dist-x86_64-netbsd/Dockerfile
@@ -1,7 +1,8 @@
-FROM ubuntu:16.04
+FROM ubuntu:20.04
 
 COPY scripts/cross-apt-packages.sh /scripts/
 RUN sh /scripts/cross-apt-packages.sh
+RUN DEBIAN_FRONTEND=noninteractive apt-get install -y zlib1g-dev
 
 COPY host-x86_64/dist-x86_64-netbsd/build-netbsd-toolchain.sh /tmp/
 RUN /tmp/build-netbsd-toolchain.sh
@@ -9,9 +10,6 @@ RUN /tmp/build-netbsd-toolchain.sh
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
-COPY scripts/cmake.sh /scripts/
-RUN /scripts/cmake.sh
-
 ENV PATH=$PATH:/x-tools/x86_64-unknown-netbsd/bin
 
 ENV \
@@ -21,6 +19,5 @@ ENV \
 
 ENV HOSTS=x86_64-unknown-netbsd
 
-ENV RUST_CONFIGURE_ARGS --enable-extended --disable-docs \
-    --set llvm.allow-old-toolchain
+ENV RUST_CONFIGURE_ARGS --enable-extended --disable-docs
 ENV SCRIPT python3 ../x.py dist --host $HOSTS --target $HOSTS
diff --git a/src/ci/docker/host-x86_64/dist-x86_64-netbsd/build-netbsd-toolchain.sh b/src/ci/docker/host-x86_64/dist-x86_64-netbsd/build-netbsd-toolchain.sh
index 5dfa47b4e..e0c008b76 100755
--- a/src/ci/docker/host-x86_64/dist-x86_64-netbsd/build-netbsd-toolchain.sh
+++ b/src/ci/docker/host-x86_64/dist-x86_64-netbsd/build-netbsd-toolchain.sh
@@ -25,19 +25,19 @@ cd netbsd
 
 mkdir -p /x-tools/x86_64-unknown-netbsd/sysroot
 
-URL=https://ci-mirrors.rust-lang.org/rustc
-
-# Originally from ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-$BSD/source/sets/*.tgz
-curl $URL/2018-03-01-netbsd-src.tgz | tar xzf -
-curl $URL/2018-03-01-netbsd-gnusrc.tgz | tar xzf -
-curl $URL/2018-03-01-netbsd-sharesrc.tgz | tar xzf -
-curl $URL/2018-03-01-netbsd-syssrc.tgz | tar xzf -
-
-# Originally from ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-$BSD/amd64/binary/sets/*.tgz
-curl $URL/2018-03-01-netbsd-base.tgz | \
-  tar xzf - -C /x-tools/x86_64-unknown-netbsd/sysroot ./usr/include ./usr/lib ./lib
-curl $URL/2018-03-01-netbsd-comp.tgz | \
-  tar xzf - -C /x-tools/x86_64-unknown-netbsd/sysroot ./usr/include ./usr/lib
+# URL=https://ci-mirrors.rust-lang.org/rustc
+
+SOURCE_URL=https://cdn.netbsd.org/pub/NetBSD/NetBSD-9.0/source/sets
+curl $SOURCE_URL/src.tgz | tar xzf -
+curl $SOURCE_URL/gnusrc.tgz | tar xzf -
+curl $SOURCE_URL/sharesrc.tgz | tar xzf -
+curl $SOURCE_URL/syssrc.tgz | tar xzf -
+
+BINARY_URL=https://cdn.netbsd.org/pub/NetBSD/NetBSD-9.0/amd64/binary/sets
+curl $BINARY_URL/base.tar.xz | \
+  tar xJf - -C /x-tools/x86_64-unknown-netbsd/sysroot ./usr/include ./usr/lib ./lib
+curl $BINARY_URL/comp.tar.xz | \
+  tar xJf - -C /x-tools/x86_64-unknown-netbsd/sysroot ./usr/include ./usr/lib
 
 cd usr/src
 
diff --git a/src/ci/docker/host-x86_64/i686-gnu-nopt/Dockerfile b/src/ci/docker/host-x86_64/i686-gnu-nopt/Dockerfile
index dd74726f8..e2b66c2cf 100644
--- a/src/ci/docker/host-x86_64/i686-gnu-nopt/Dockerfile
+++ b/src/ci/docker/host-x86_64/i686-gnu-nopt/Dockerfile
@@ -15,7 +15,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   gdb \
   zlib1g-dev \
   lib32z1-dev \
-  xz-utils
+  xz-utils \
+  && rm -rf /var/lib/apt/lists/*
 
 
 COPY scripts/sccache.sh /scripts/
diff --git a/src/ci/docker/host-x86_64/i686-gnu/Dockerfile b/src/ci/docker/host-x86_64/i686-gnu/Dockerfile
index 0c36cfd66..cb6559707 100644
--- a/src/ci/docker/host-x86_64/i686-gnu/Dockerfile
+++ b/src/ci/docker/host-x86_64/i686-gnu/Dockerfile
@@ -15,7 +15,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   gdb \
   zlib1g-dev \
   lib32z1-dev \
-  xz-utils
+  xz-utils \
+  && rm -rf /var/lib/apt/lists/*
 
 
 COPY scripts/sccache.sh /scripts/
diff --git a/src/ci/docker/host-x86_64/mingw-check/Dockerfile b/src/ci/docker/host-x86_64/mingw-check/Dockerfile
index 52a777615..40caa7c50 100644
--- a/src/ci/docker/host-x86_64/mingw-check/Dockerfile
+++ b/src/ci/docker/host-x86_64/mingw-check/Dockerfile
@@ -20,20 +20,20 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   xz-utils \
   libssl-dev \
   pkg-config \
-  mingw-w64
+  mingw-w64 \
+  && rm -rf /var/lib/apt/lists/*
 
 RUN curl -sL https://nodejs.org/dist/v16.9.0/node-v16.9.0-linux-x64.tar.xz | tar -xJ
 ENV PATH="/node-v16.9.0-linux-x64/bin:${PATH}"
 # Install es-check
 # Pin its version to prevent unrelated CI failures due to future es-check versions.
-RUN npm install es-check@6.1.1 -g
-RUN npm install eslint@8.6.0 -g
+RUN npm install es-check@6.1.1 eslint@8.6.0 -g
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
 
 COPY host-x86_64/mingw-check/reuse-requirements.txt /tmp/
-RUN pip3 install --no-deps --require-hashes -r /tmp/reuse-requirements.txt
+RUN pip3 install --no-deps --no-cache-dir --require-hashes -r /tmp/reuse-requirements.txt
 
 COPY host-x86_64/mingw-check/validate-toolstate.sh /scripts/
 COPY host-x86_64/mingw-check/validate-error-codes.sh /scripts/
diff --git a/src/ci/docker/host-x86_64/test-various/Dockerfile b/src/ci/docker/host-x86_64/test-various/Dockerfile
index b75e2f085..cf4451f8b 100644
--- a/src/ci/docker/host-x86_64/test-various/Dockerfile
+++ b/src/ci/docker/host-x86_64/test-various/Dockerfile
@@ -1,6 +1,7 @@
 FROM ubuntu:20.04
 
 RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+  clang-11 \
   g++ \
   make \
   ninja-build \
@@ -16,11 +17,21 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-ins
   pkg-config \
   xz-utils \
   wget \
-  patch
+  patch \
+  ovmf \
+  qemu-efi-aarch64 \
+  qemu-system-arm \
+  qemu-system-x86 \
+  && rm -rf /var/lib/apt/lists/*
 
 RUN curl -sL https://nodejs.org/dist/v15.14.0/node-v15.14.0-linux-x64.tar.xz | \
   tar -xJ
 
+# Install 32-bit OVMF files for the i686-unknown-uefi test. This package
+# is not available in ubuntu 20.04, so download a 22.04 package.
+RUN curl -sL --output ovmf-ia32.deb http://mirrors.kernel.org/ubuntu/pool/universe/e/edk2/ovmf-ia32_2022.02-3_all.deb
+RUN dpkg -i ovmf-ia32.deb && rm ovmf-ia32.deb
+
 WORKDIR /build/
 COPY scripts/musl-patch-configure.diff /build/
 COPY scripts/musl-toolchain.sh /build/
@@ -64,4 +75,15 @@ ENV MUSL_TARGETS=x86_64-unknown-linux-musl \
     CXX_x86_64_unknown_linux_musl=x86_64-linux-musl-g++
 ENV MUSL_SCRIPT python3 /checkout/x.py --stage 2 test --host='' --target $MUSL_TARGETS
 
-ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT
+COPY host-x86_64/test-various/uefi_qemu_test /uefi_qemu_test
+ENV UEFI_TARGETS=aarch64-unknown-uefi,i686-unknown-uefi,x86_64-unknown-uefi \
+    CC_aarch64_unknown_uefi=clang-11 \
+    CXX_aarch64_unknown_uefi=clang++-11 \
+    CC_i686_unknown_uefi=clang-11 \
+    CXX_i686_unknown_uefi=clang++-11 \
+    CC_x86_64_unknown_uefi=clang-11 \
+    CXX_x86_64_unknown_uefi=clang++-11
+ENV UEFI_SCRIPT python3 /checkout/x.py --stage 2 build --host='' --target $UEFI_TARGETS && \
+  python3 -u /uefi_qemu_test/run.py
+
+ENV SCRIPT $WASM_SCRIPT && $NVPTX_SCRIPT && $MUSL_SCRIPT && $UEFI_SCRIPT
diff --git a/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/Cargo.toml b/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/Cargo.toml
new file mode 100644
index 000000000..fa8e5b3d0
--- /dev/null
+++ b/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "uefi_qemu_test"
+version = "0.0.0"
+edition = "2021"
+
+[workspace]
+
+[dependencies]
+r-efi = "4.1.0"
diff --git a/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/run.py b/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/run.py
new file mode 100644
index 000000000..ffae7b0d4
--- /dev/null
+++ b/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/run.py
@@ -0,0 +1,142 @@
+#!/usr/bin/env python3
+
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+from pathlib import Path
+
+TARGET_AARCH64 = 'aarch64-unknown-uefi'
+TARGET_I686 = 'i686-unknown-uefi'
+TARGET_X86_64 = 'x86_64-unknown-uefi'
+
+def run(*cmd, capture=False, check=True, env=None, timeout=None):
+    """Print and run a command, optionally capturing the output."""
+    cmd = [str(p) for p in cmd]
+    print(' '.join(cmd))
+    return subprocess.run(cmd,
+                          capture_output=capture,
+                          check=check,
+                          env=env,
+                          text=True,
+                          timeout=timeout)
+
+def build_and_run(tmp_dir, target):
+    if target == TARGET_AARCH64:
+        boot_file_name = 'bootaa64.efi'
+        ovmf_dir = Path('/usr/share/AAVMF')
+        ovmf_code = 'AAVMF_CODE.fd'
+        ovmf_vars = 'AAVMF_VARS.fd'
+        qemu = 'qemu-system-aarch64'
+        machine = 'virt'
+        cpu = 'cortex-a72'
+    elif target == TARGET_I686:
+        boot_file_name = 'bootia32.efi'
+        ovmf_dir = Path('/usr/share/OVMF')
+        ovmf_code = 'OVMF32_CODE_4M.secboot.fd'
+        ovmf_vars = 'OVMF32_VARS_4M.fd'
+        # The i686 target intentionally uses 64-bit qemu; the important
+        # difference is that the OVMF code provides a 32-bit environment.
+        qemu = 'qemu-system-x86_64'
+        machine = 'q35'
+        cpu = 'qemu64'
+    elif target == TARGET_X86_64:
+        boot_file_name = 'bootx64.efi'
+        ovmf_dir = Path('/usr/share/OVMF')
+        ovmf_code = 'OVMF_CODE.fd'
+        ovmf_vars = 'OVMF_VARS.fd'
+        qemu = 'qemu-system-x86_64'
+        machine = 'q35'
+        cpu = 'qemu64'
+    else:
+        raise KeyError('invalid target')
+
+    host_artifacts = Path('/checkout/obj/build/x86_64-unknown-linux-gnu')
+    stage0 = host_artifacts / 'stage0/bin'
+    stage2 = host_artifacts / 'stage2/bin'
+
+    env = dict(os.environ)
+    env['PATH'] = '{}:{}:{}'.format(stage2, stage0, env['PATH'])
+
+    # Copy the test create into `tmp_dir`.
+    test_crate = Path(tmp_dir) / 'uefi_qemu_test'
+    shutil.copytree('/uefi_qemu_test', test_crate)
+
+    # Build the UEFI executable.
+    run('cargo',
+        'build',
+        '--manifest-path',
+        test_crate / 'Cargo.toml',
+        '--target',
+        target,
+        env=env)
+
+    # Create a mock EFI System Partition in a subdirectory.
+    esp = test_crate / 'esp'
+    boot = esp / 'efi/boot'
+    os.makedirs(boot, exist_ok=True)
+
+    # Copy the executable into the ESP.
+    src_exe_path = test_crate / 'target' / target / 'debug/uefi_qemu_test.efi'
+    shutil.copy(src_exe_path, boot / boot_file_name)
+    print(src_exe_path, boot / boot_file_name)
+
+    # Select the appropriate EDK2 build.
+    ovmf_code = ovmf_dir / ovmf_code
+    ovmf_vars = ovmf_dir / ovmf_vars
+
+    # Make a writable copy of the vars file. aarch64 doesn't boot
+    # correctly with read-only vars.
+    ovmf_rw_vars = Path(tmp_dir) / 'vars.fd'
+    shutil.copy(ovmf_vars, ovmf_rw_vars)
+
+    # Run the executable in QEMU and capture the output.
+    output = run(qemu,
+                 '-machine',
+                 machine,
+                 '-cpu',
+                 cpu,
+                 '-display',
+                 'none',
+                 '-serial',
+                 'stdio',
+                 '-drive',
+                 f'if=pflash,format=raw,readonly=on,file={ovmf_code}',
+                 '-drive',
+                 f'if=pflash,format=raw,readonly=off,file={ovmf_rw_vars}',
+                 '-drive',
+                 f'format=raw,file=fat:rw:{esp}',
+                 capture=True,
+                 # Ubuntu 20.04 (which is what the Dockerfile currently
+                 # uses) provides QEMU 4.2.1, which segfaults on
+                 # shutdown under some circumstances. That has been
+                 # fixed in newer versions of QEMU, but for now just
+                 # don't check the exit status.
+                 check=False,
+                 # Set a timeout to kill the VM in case something goes wrong.
+                 timeout=60).stdout
+
+    if 'Hello World!' in output:
+        print('VM produced expected output')
+    else:
+        print('unexpected VM output:')
+        print('---start---')
+        print(output)
+        print('---end---')
+        sys.exit(1)
+
+
+def main():
+    targets = [TARGET_AARCH64, TARGET_I686, TARGET_X86_64]
+
+    for target in targets:
+        # Create a temporary directory so that we have a writeable
+        # workspace.
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            build_and_run(tmp_dir, target)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/src/main.rs b/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/src/main.rs
new file mode 100644
index 000000000..2ec554c14
--- /dev/null
+++ b/src/ci/docker/host-x86_64/test-various/uefi_qemu_test/src/main.rs
@@ -0,0 +1,45 @@
+// Code is adapted from this hello world example:
+// https://doc.rust-lang.org/nightly/rustc/platform-support/unknown-uefi.html
+
+#![no_main]
+#![no_std]
+
+use core::{panic, ptr};
+use r_efi::efi::{Char16, Handle, Status, SystemTable, RESET_SHUTDOWN};
+
+#[panic_handler]
+fn panic_handler(_info: &panic::PanicInfo) -> ! {
+    loop {}
+}
+
+#[export_name = "efi_main"]
+pub extern "C" fn main(_h: Handle, st: *mut SystemTable) -> Status {
+    let s = [
+        0x0048u16, 0x0065u16, 0x006cu16, 0x006cu16, 0x006fu16, // "Hello"
+        0x0020u16, //                                             " "
+        0x0057u16, 0x006fu16, 0x0072u16, 0x006cu16, 0x0064u16, // "World"
+        0x0021u16, //                                             "!"
+        0x000au16, //                                             "\n"
+        0x0000u16, //                                             NUL
+    ];
+
+    // Print "Hello World!".
+    let r = unsafe { ((*(*st).con_out).output_string)((*st).con_out, s.as_ptr() as *mut Char16) };
+    if r.is_error() {
+        return r;
+    }
+
+    // Shut down.
+    unsafe {
+        ((*((*st).runtime_services)).reset_system)(
+            RESET_SHUTDOWN,
+            Status::SUCCESS,
+            0,
+            ptr::null_mut(),
+        );
+    }
+
+    // This should never be reached because `reset_system` should never
+    // return, so fail with an error if we get here.
+    Status::UNSUPPORTED
+}
diff --git a/src/ci/docker/host-x86_64/wasm32/Dockerfile b/src/ci/docker/host-x86_64/wasm32/Dockerfile
index 9e37c2822..ef1fde1c3 100644
--- a/src/ci/docker/host-x86_64/wasm32/Dockerfile
+++ b/src/ci/docker/host-x86_64/wasm32/Dockerfile
@@ -13,7 +13,8 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-ins
   sudo \
   gdb \
   xz-utils \
-  bzip2
+  bzip2 \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/emscripten.sh /scripts/
 RUN bash /scripts/emscripten.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-aux/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-aux/Dockerfile
index d55d5b56a..e08c4e1e8 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-aux/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-aux/Dockerfile
@@ -19,7 +19,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   llvm-dev \
   libfreetype6-dev \
   libexpat1-dev \
-  tidy
+  tidy \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile
index 739045248..c2b002055 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-debug/Dockerfile
@@ -23,7 +23,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   pkg-config \
   xz-utils \
   lld \
-  clang
+  clang \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-distcheck/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-distcheck/Dockerfile
index 80a004501..7e640c49f 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-distcheck/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-distcheck/Dockerfile
@@ -15,7 +15,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   gdb \
   xz-utils \
   libssl-dev \
-  pkg-config
+  pkg-config \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile
index 1289f116f..16976a942 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13-stage1/Dockerfile
@@ -21,7 +21,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     pkg-config \
     zlib1g-dev \
     xz-utils \
-    nodejs
+    nodejs \
+    && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
@@ -29,7 +30,6 @@ RUN sh /scripts/sccache.sh
 # We are disabling CI LLVM since this builder is intentionally using a host
 # LLVM, rather than the typical src/llvm-project LLVM.
 ENV NO_DOWNLOAD_CI_LLVM 1
-ENV EXTERNAL_LLVM 1
 
 # Using llvm-link-shared due to libffi issues -- see #34486
 ENV RUST_CONFIGURE_ARGS \
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile
index 4b89a72ba..06f15bd12 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-llvm-13/Dockerfile
@@ -24,15 +24,15 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   pkg-config \
   zlib1g-dev \
   xz-utils \
-  nodejs
-
+  nodejs \
+  \
 # Install powershell so we can test x.ps1 on Linux
-RUN apt-get update && \
-    apt-get install -y apt-transport-https software-properties-common && \
+    apt-transport-https software-properties-common && \
     curl -s "https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb" > packages-microsoft-prod.deb && \
     dpkg -i packages-microsoft-prod.deb && \
     apt-get update && \
-    apt-get install -y powershell
+    apt-get install -y powershell \
+    && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
@@ -40,7 +40,6 @@ RUN sh /scripts/sccache.sh
 # We are disabling CI LLVM since this builder is intentionally using a host
 # LLVM, rather than the typical src/llvm-project LLVM.
 ENV NO_DOWNLOAD_CI_LLVM 1
-ENV EXTERNAL_LLVM 1
 
 # Using llvm-link-shared due to libffi issues -- see #34486
 ENV RUST_CONFIGURE_ARGS \
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-nopt/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-nopt/Dockerfile
index 77510d7ac..9fdc78406 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-nopt/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-nopt/Dockerfile
@@ -15,7 +15,8 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-ins
   gdb \
   libssl-dev \
   pkg-config \
-  xz-utils
+  xz-utils \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile
index 4350ca205..58c0c5db1 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/Dockerfile
@@ -14,10 +14,9 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   libssl-dev \
   sudo \
   xz-utils \
-  tidy
-
+  tidy \
+  \
 # Install dependencies for chromium browser
-RUN apt-get install -y \
   gconf-service \
   libasound2 \
   libatk1.0-0 \
@@ -56,7 +55,8 @@ RUN apt-get install -y \
   libnss3 \
   lsb-release \
   xdg-utils \
-  wget
+  wget \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version b/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
index cc96715b2..3f8dcd03d 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
@@ -1 +1 @@
-0.12.7
\ No newline at end of file
+0.13.2
\ No newline at end of file
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh b/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
index 80a066cac..7dde63709 100755
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
@@ -27,6 +27,7 @@ python3 "$X_PY" test --stage 2 src/tools/rustfmt
 python3 "$X_PY" test --stage 2 src/tools/miri
 # We natively run this script on x86_64-unknown-linux-gnu and x86_64-pc-windows-msvc.
 # Also cover some other targets (on both of these hosts) via cross-testing.
+export BOOTSTRAP_SKIP_TARGET_SANITY=1 # we don't need `cc` for these targets
 python3 "$X_PY" test --stage 2 src/tools/miri --target i686-pc-windows-msvc
-#FIXME(https://github.com/rust-lang/rust/issues/103519): macOS testing is currently disabled
-# python3 "$X_PY" test --stage 2 src/tools/miri --target aarch64-apple-darwin
+python3 "$X_PY" test --stage 2 src/tools/miri --target aarch64-apple-darwin
+unset BOOTSTRAP_SKIP_TARGET_SANITY
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu/Dockerfile b/src/ci/docker/host-x86_64/x86_64-gnu/Dockerfile
index 88c182a4d..5b9581f72 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu/Dockerfile
+++ b/src/ci/docker/host-x86_64/x86_64-gnu/Dockerfile
@@ -15,7 +15,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   gdb \
   libssl-dev \
   pkg-config \
-  xz-utils
+  xz-utils \
+  && rm -rf /var/lib/apt/lists/*
 
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh
diff --git a/src/ci/docker/scripts/freebsd-toolchain.sh b/src/ci/docker/scripts/freebsd-toolchain.sh
index 4a4cac1b7..17cd456b9 100755
--- a/src/ci/docker/scripts/freebsd-toolchain.sh
+++ b/src/ci/docker/scripts/freebsd-toolchain.sh
@@ -53,7 +53,7 @@ files_to_extract=(
 for lib in c cxxrt gcc_s m thr util; do
   files_to_extract=("${files_to_extract[@]}" "./lib/lib${lib}.*" "./usr/lib/lib${lib}.*")
 done
-for lib in c++ c_nonshared compiler_rt execinfo gcc pthread rt ssp_nonshared procstat devstat kvm; do
+for lib in c++ c_nonshared compiler_rt execinfo gcc pthread rt ssp_nonshared procstat devstat kvm memstat; do
   files_to_extract=("${files_to_extract[@]}" "./usr/lib/lib${lib}.*")
 done
 
diff --git a/src/ci/docker/scripts/fuchsia-test-runner.py b/src/ci/docker/scripts/fuchsia-test-runner.py
new file mode 100755
index 000000000..a2708d169
--- /dev/null
+++ b/src/ci/docker/scripts/fuchsia-test-runner.py
@@ -0,0 +1,1041 @@
+#!/usr/bin/env python3
+
+"""
+The Rust toolchain test runner for Fuchsia.
+
+For instructions on running the compiler test suite, see
+https://doc.rust-lang.org/stable/rustc/platform-support/fuchsia.html#aarch64-fuchsia-and-x86_64-fuchsia
+"""
+
+import argparse
+from dataclasses import dataclass
+import glob
+import hashlib
+import json
+import os
+import platform
+import re
+import shutil
+import signal
+import subprocess
+import sys
+from typing import ClassVar, List
+
+
+@dataclass
+class TestEnvironment:
+    rust_dir: str
+    sdk_dir: str
+    target_arch: str
+    package_server_pid: int = None
+    emu_addr: str = None
+    libstd_name: str = None
+    libtest_name: str = None
+    verbose: bool = False
+
+    @staticmethod
+    def tmp_dir():
+        tmp_dir = os.environ.get("TEST_TOOLCHAIN_TMP_DIR")
+        if tmp_dir is not None:
+            return os.path.abspath(tmp_dir)
+        return os.path.join(os.path.dirname(__file__), "tmp~")
+
+    @classmethod
+    def env_file_path(cls):
+        return os.path.join(cls.tmp_dir(), "test_env.json")
+
+    @classmethod
+    def from_args(cls, args):
+        return cls(
+            os.path.abspath(args.rust),
+            os.path.abspath(args.sdk),
+            args.target_arch,
+            verbose=args.verbose,
+        )
+
+    @classmethod
+    def read_from_file(cls):
+        with open(cls.env_file_path(), encoding="utf-8") as f:
+            test_env = json.loads(f.read())
+            return cls(
+                test_env["rust_dir"],
+                test_env["sdk_dir"],
+                test_env["target_arch"],
+                libstd_name=test_env["libstd_name"],
+                libtest_name=test_env["libtest_name"],
+                emu_addr=test_env["emu_addr"],
+                package_server_pid=test_env["package_server_pid"],
+                verbose=test_env["verbose"],
+            )
+
+    def image_name(self):
+        if self.target_arch == "x64":
+            return "qemu-x64"
+        if self.target_arch == "arm64":
+            return "qemu-arm64"
+        raise Exception(f"Unrecognized target architecture {self.target_arch}")
+
+    def write_to_file(self):
+        with open(self.env_file_path(), "w", encoding="utf-8") as f:
+            f.write(json.dumps(self.__dict__))
+
+    def ssh_dir(self):
+        return os.path.join(self.tmp_dir(), "ssh")
+
+    def ssh_keyfile_path(self):
+        return os.path.join(self.ssh_dir(), "fuchsia_ed25519")
+
+    def ssh_authfile_path(self):
+        return os.path.join(self.ssh_dir(), "fuchsia_authorized_keys")
+
+    def vdl_output_path(self):
+        return os.path.join(self.tmp_dir(), "vdl_output")
+
+    def package_server_log_path(self):
+        return os.path.join(self.tmp_dir(), "package_server_log")
+
+    def emulator_log_path(self):
+        return os.path.join(self.tmp_dir(), "emulator_log")
+
+    def packages_dir(self):
+        return os.path.join(self.tmp_dir(), "packages")
+
+    def output_dir(self):
+        return os.path.join(self.tmp_dir(), "output")
+
+    TEST_REPO_NAME: ClassVar[str] = "rust-testing"
+
+    def repo_dir(self):
+        return os.path.join(self.tmp_dir(), self.TEST_REPO_NAME)
+
+    def rustlib_dir(self):
+        if self.target_arch == "x64":
+            return "x86_64-fuchsia"
+        if self.target_arch == "arm64":
+            return "aarch64-fuchsia"
+        raise Exception(f"Unrecognized target architecture {self.target_arch}")
+
+    def libs_dir(self):
+        return os.path.join(
+            self.rust_dir,
+            "lib",
+        )
+
+    def rustlibs_dir(self):
+        return os.path.join(
+            self.libs_dir(),
+            "rustlib",
+            self.rustlib_dir(),
+            "lib",
+        )
+
+    def sdk_arch(self):
+        machine = platform.machine()
+        if machine == "x86_64":
+            return "x64"
+        if machine == "arm":
+            return "a64"
+        raise Exception(f"Unrecognized host architecture {machine}")
+
+    def tool_path(self, tool):
+        return os.path.join(self.sdk_dir, "tools", self.sdk_arch(), tool)
+
+    def host_arch_triple(self):
+        machine = platform.machine()
+        if machine == "x86_64":
+            return "x86_64-unknown-linux-gnu"
+        if machine == "arm":
+            return "aarch64-unknown-linux-gnu"
+        raise Exception(f"Unrecognized host architecture {machine}")
+
+    def zxdb_script_path(self):
+        return os.path.join(self.tmp_dir(), "zxdb_script")
+
+    def log_info(self, msg):
+        print(msg)
+
+    def log_debug(self, msg):
+        if self.verbose:
+            print(msg)
+
+    def subprocess_output(self):
+        if self.verbose:
+            return sys.stdout
+        return subprocess.DEVNULL
+
+    def ffx_daemon_log_path(self):
+        return os.path.join(self.tmp_dir(), "ffx_daemon_log")
+
+    def ffx_isolate_dir(self):
+        return os.path.join(self.tmp_dir(), "ffx_isolate")
+
+    def ffx_home_dir(self):
+        return os.path.join(self.ffx_isolate_dir(), "user-home")
+
+    def ffx_tmp_dir(self):
+        return os.path.join(self.ffx_isolate_dir(), "tmp")
+
+    def ffx_log_dir(self):
+        return os.path.join(self.ffx_isolate_dir(), "log")
+
+    def ffx_user_config_dir(self):
+        return os.path.join(self.ffx_xdg_config_home(), "Fuchsia", "ffx", "config")
+
+    def ffx_user_config_path(self):
+        return os.path.join(self.ffx_user_config_dir(), "config.json")
+
+    def ffx_xdg_config_home(self):
+        if platform.system() == "Darwin":
+            return os.path.join(self.ffx_home_dir(), "Library", "Preferences")
+        return os.path.join(self.ffx_home_dir(), ".local", "share")
+
+    def ffx_ascendd_path(self):
+        return os.path.join(self.ffx_tmp_dir(), "ascendd")
+
+    def start_ffx_isolation(self):
+        # Most of this is translated directly from ffx's isolate library
+        os.mkdir(self.ffx_isolate_dir())
+        os.mkdir(self.ffx_home_dir())
+        os.mkdir(self.ffx_tmp_dir())
+        os.mkdir(self.ffx_log_dir())
+
+        fuchsia_dir = os.path.join(self.ffx_home_dir(), ".fuchsia")
+        os.mkdir(fuchsia_dir)
+
+        fuchsia_debug_dir = os.path.join(fuchsia_dir, "debug")
+        os.mkdir(fuchsia_debug_dir)
+
+        metrics_dir = os.path.join(fuchsia_dir, "metrics")
+        os.mkdir(metrics_dir)
+
+        analytics_path = os.path.join(metrics_dir, "analytics-status")
+        with open(analytics_path, "w", encoding="utf-8") as analytics_file:
+            print("0", file=analytics_file)
+
+        ffx_path = os.path.join(metrics_dir, "ffx")
+        with open(ffx_path, "w", encoding="utf-8") as ffx_file:
+            print("1", file=ffx_file)
+
+        os.makedirs(self.ffx_user_config_dir())
+
+        with open(
+            self.ffx_user_config_path(), "w", encoding="utf-8"
+        ) as config_json_file:
+            user_config_for_test = {
+                "log": {
+                    "enabled": True,
+                    "dir": self.ffx_log_dir(),
+                },
+                "overnet": {
+                    "socket": self.ffx_ascendd_path(),
+                },
+                "ssh": {
+                    "pub": self.ssh_authfile_path(),
+                    "priv": self.ssh_keyfile_path(),
+                },
+                "test": {
+                    "is_isolated": True,
+                    "experimental_structured_output": True,
+                },
+            }
+            print(json.dumps(user_config_for_test), file=config_json_file)
+
+        ffx_env_path = os.path.join(self.ffx_user_config_dir(), ".ffx_env")
+        with open(ffx_env_path, "w", encoding="utf-8") as ffx_env_file:
+            ffx_env_config_for_test = {
+                "user": self.ffx_user_config_path(),
+                "build": None,
+                "global": None,
+            }
+            print(json.dumps(ffx_env_config_for_test), file=ffx_env_file)
+
+        # Start ffx daemon
+        # We want this to be a long-running process that persists after the script finishes
+        # pylint: disable=consider-using-with
+        with open(
+            self.ffx_daemon_log_path(), "w", encoding="utf-8"
+        ) as ffx_daemon_log_file:
+            subprocess.Popen(
+                [
+                    self.tool_path("ffx"),
+                    "--config",
+                    self.ffx_user_config_path(),
+                    "daemon",
+                    "start",
+                ],
+                env=self.ffx_cmd_env(),
+                stdout=ffx_daemon_log_file,
+                stderr=ffx_daemon_log_file,
+            )
+
+    def ffx_cmd_env(self):
+        result = {
+            "HOME": self.ffx_home_dir(),
+            "XDG_CONFIG_HOME": self.ffx_xdg_config_home(),
+            "ASCENDD": self.ffx_ascendd_path(),
+            "FUCHSIA_SSH_KEY": self.ssh_keyfile_path(),
+            # We want to use our own specified temp directory
+            "TMP": self.tmp_dir(),
+            "TEMP": self.tmp_dir(),
+            "TMPDIR": self.tmp_dir(),
+            "TEMPDIR": self.tmp_dir(),
+        }
+
+        return result
+
+    def stop_ffx_isolation(self):
+        subprocess.check_call(
+            [
+                self.tool_path("ffx"),
+                "--config",
+                self.ffx_user_config_path(),
+                "daemon",
+                "stop",
+            ],
+            env=self.ffx_cmd_env(),
+            stdout=self.subprocess_output(),
+            stderr=self.subprocess_output(),
+        )
+
+    def start(self):
+        """Sets up the testing environment and prepares to run tests.
+
+        Args:
+            args: The command-line arguments to this command.
+
+        During setup, this function will:
+        - Locate necessary shared libraries
+        - Create a new temp directory (this is where all temporary files are stored)
+        - Start an emulator
+        - Start an update server
+        - Create a new package repo and register it with the emulator
+        - Write test environment settings to a temporary file
+        """
+
+        # Initialize temp directory
+        if not os.path.exists(self.tmp_dir()):
+            os.mkdir(self.tmp_dir())
+        elif len(os.listdir(self.tmp_dir())) != 0:
+            raise Exception(f"Temp directory is not clean (in {self.tmp_dir()})")
+
+        os.mkdir(self.ssh_dir())
+        os.mkdir(self.output_dir())
+
+        # Find libstd and libtest
+        libstd_paths = glob.glob(os.path.join(self.rustlibs_dir(), "libstd-*.so"))
+        libtest_paths = glob.glob(os.path.join(self.rustlibs_dir(), "libtest-*.so"))
+
+        if not libstd_paths:
+            raise Exception(f"Failed to locate libstd (in {self.rustlibs_dir()})")
+
+        if not libtest_paths:
+            raise Exception(f"Failed to locate libtest (in {self.rustlibs_dir()})")
+
+        self.libstd_name = os.path.basename(libstd_paths[0])
+        self.libtest_name = os.path.basename(libtest_paths[0])
+
+        # Generate SSH keys for the emulator to use
+        self.log_info("Generating SSH keys...")
+        subprocess.check_call(
+            [
+                "ssh-keygen",
+                "-N",
+                "",
+                "-t",
+                "ed25519",
+                "-f",
+                self.ssh_keyfile_path(),
+                "-C",
+                "Generated by test_toolchain.py",
+            ],
+            stdout=self.subprocess_output(),
+            stderr=self.subprocess_output(),
+        )
+        authfile_contents = subprocess.check_output(
+            [
+                "ssh-keygen",
+                "-y",
+                "-f",
+                self.ssh_keyfile_path(),
+            ],
+            stderr=self.subprocess_output(),
+        )
+        with open(self.ssh_authfile_path(), "wb") as authfile:
+            authfile.write(authfile_contents)
+
+        # Start ffx isolation
+        self.log_info("Starting ffx isolation...")
+        self.start_ffx_isolation()
+
+        # Start emulator (this will generate the vdl output)
+        self.log_info("Starting emulator...")
+        subprocess.check_call(
+            [
+                self.tool_path("fvdl"),
+                "--sdk",
+                "start",
+                "--tuntap",
+                "--headless",
+                "--nointeractive",
+                "--ssh",
+                self.ssh_dir(),
+                "--vdl-output",
+                self.vdl_output_path(),
+                "--emulator-log",
+                self.emulator_log_path(),
+                "--image-name",
+                self.image_name(),
+            ],
+            stdout=self.subprocess_output(),
+            stderr=self.subprocess_output(),
+        )
+
+        # Parse vdl output for relevant information
+        with open(self.vdl_output_path(), encoding="utf-8") as f:
+            vdl_content = f.read()
+            matches = re.search(
+                r'network_address:\s+"\[([0-9a-f]{1,4}:(:[0-9a-f]{1,4}){4}%qemu)\]"',
+                vdl_content,
+            )
+            self.emu_addr = matches.group(1)
+
+        # Create new package repo
+        self.log_info("Creating package repo...")
+        subprocess.check_call(
+            [
+                self.tool_path("pm"),
+                "newrepo",
+                "-repo",
+                self.repo_dir(),
+            ],
+            stdout=self.subprocess_output(),
+            stderr=self.subprocess_output(),
+        )
+
+        # Start package server
+        self.log_info("Starting package server...")
+        with open(
+            self.package_server_log_path(), "w", encoding="utf-8"
+        ) as package_server_log:
+            # We want this to be a long-running process that persists after the script finishes
+            # pylint: disable=consider-using-with
+            self.package_server_pid = subprocess.Popen(
+                [
+                    self.tool_path("pm"),
+                    "serve",
+                    "-vt",
+                    "-repo",
+                    self.repo_dir(),
+                    "-l",
+                    ":8084",
+                ],
+                stdout=package_server_log,
+                stderr=package_server_log,
+            ).pid
+
+        # Register package server with emulator
+        self.log_info("Registering package server...")
+        ssh_client = subprocess.check_output(
+            [
+                "ssh",
+                "-i",
+                self.ssh_keyfile_path(),
+                "-o",
+                "StrictHostKeyChecking=accept-new",
+                self.emu_addr,
+                "-f",
+                "echo $SSH_CLIENT",
+            ],
+            text=True,
+        )
+        repo_addr = ssh_client.split()[0].replace("%", "%25")
+        repo_url = f"http://[{repo_addr}]:8084/config.json"
+        subprocess.check_call(
+            [
+                "ssh",
+                "-i",
+                self.ssh_keyfile_path(),
+                "-o",
+                "StrictHostKeyChecking=accept-new",
+                self.emu_addr,
+                "-f",
+                f"pkgctl repo add url -f 1 -n {self.TEST_REPO_NAME} {repo_url}",
+            ],
+            stdout=self.subprocess_output(),
+            stderr=self.subprocess_output(),
+        )
+
+        # Write to file
+        self.write_to_file()
+
+        self.log_info("Success! Your environment is ready to run tests.")
+
+    # FIXME: shardify this
+    # `facet` statement required for TCP testing via
+    # protocol `fuchsia.posix.socket.Provider`. See
+    # https://fuchsia.dev/fuchsia-src/development/testing/components/test_runner_framework?hl=en#legacy_non-hermetic_tests
+    CML_TEMPLATE: ClassVar[
+        str
+    ] = """
+    {{
+        program: {{
+            runner: "elf_test_runner",
+            binary: "bin/{exe_name}",
+            forward_stderr_to: "log",
+            forward_stdout_to: "log",
+            environ: [{env_vars}
+            ]
+        }},
+        capabilities: [
+            {{ protocol: "fuchsia.test.Suite" }},
+        ],
+        expose: [
+            {{
+                protocol: "fuchsia.test.Suite",
+                from: "self",
+            }},
+        ],
+        use: [
+            {{ storage: "data", path: "/data" }},
+            {{ protocol: [ "fuchsia.process.Launcher" ] }},
+            {{ protocol: [ "fuchsia.posix.socket.Provider" ] }}
+        ],
+        facets: {{
+            "fuchsia.test": {{ type: "system" }},
+        }},
+    }}
+    """
+
+    MANIFEST_TEMPLATE = """
+    meta/package={package_dir}/meta/package
+    meta/{package_name}.cm={package_dir}/meta/{package_name}.cm
+    bin/{exe_name}={bin_path}
+    lib/{libstd_name}={rust_dir}/lib/rustlib/{rustlib_dir}/lib/{libstd_name}
+    lib/{libtest_name}={rust_dir}/lib/rustlib/{rustlib_dir}/lib/{libtest_name}
+    lib/ld.so.1={sdk_dir}/arch/{target_arch}/sysroot/lib/libc.so
+    lib/libzircon.so={sdk_dir}/arch/{target_arch}/sysroot/lib/libzircon.so
+    lib/libfdio.so={sdk_dir}/arch/{target_arch}/lib/libfdio.so
+    """
+
+    TEST_ENV_VARS: ClassVar[List[str]] = [
+        "TEST_EXEC_ENV",
+        "RUST_MIN_STACK",
+        "RUST_BACKTRACE",
+        "RUST_NEWRT",
+        "RUST_LOG",
+        "RUST_TEST_THREADS",
+    ]
+
+    def run(self, args):
+        """Runs the requested test in the testing environment.
+
+        Args:
+        args: The command-line arguments to this command.
+        Returns:
+        The return code of the test (0 for success, else failure).
+
+        To run a test, this function will:
+        - Create, compile, archive, and publish a test package
+        - Run the test package on the emulator
+        - Forward the test's stdout and stderr as this script's stdout and stderr
+        """
+
+        bin_path = os.path.abspath(args.bin_path)
+
+        # Build a unique, deterministic name for the test using the name of the
+        # binary and the last 6 hex digits of the hash of the full path
+        def path_checksum(path):
+            m = hashlib.sha256()
+            m.update(path.encode("utf-8"))
+            return m.hexdigest()[0:6]
+
+        base_name = os.path.basename(os.path.dirname(args.bin_path))
+        exe_name = base_name.lower().replace(".", "_")
+        package_name = f"{exe_name}_{path_checksum(bin_path)}"
+
+        package_dir = os.path.join(self.packages_dir(), package_name)
+        cml_path = os.path.join(package_dir, "meta", f"{package_name}.cml")
+        cm_path = os.path.join(package_dir, "meta", f"{package_name}.cm")
+        manifest_path = os.path.join(package_dir, f"{package_name}.manifest")
+        far_path = os.path.join(package_dir, f"{package_name}-0.far")
+
+        shared_libs = args.shared_libs[: args.n]
+        arguments = args.shared_libs[args.n :]
+
+        test_output_dir = os.path.join(self.output_dir(), package_name)
+
+        # Clean and create temporary output directory
+        if os.path.exists(test_output_dir):
+            shutil.rmtree(test_output_dir)
+
+        os.mkdir(test_output_dir)
+
+        # Open log file
+        log_path = os.path.join(test_output_dir, "log")
+        with open(log_path, "w", encoding="utf-8") as log_file:
+
+            def log(msg):
+                print(msg, file=log_file)
+                log_file.flush()
+
+            log(f"Bin path: {bin_path}")
+
+            log("Setting up package...")
+
+            # Set up package
+            subprocess.check_call(
+                [
+                    self.tool_path("pm"),
+                    "-o",
+                    package_dir,
+                    "-n",
+                    package_name,
+                    "init",
+                ],
+                stdout=log_file,
+                stderr=log_file,
+            )
+
+            log("Writing CML...")
+
+            # Write and compile CML
+            with open(cml_path, "w", encoding="utf-8") as cml:
+                # Collect environment variables
+                env_vars = ""
+                for var_name in self.TEST_ENV_VARS:
+                    var_value = os.getenv(var_name)
+                    if var_value is not None:
+                        env_vars += f'\n            "{var_name}={var_value}",'
+
+                # Default to no backtrace for test suite
+                if os.getenv("RUST_BACKTRACE") == None:
+                    env_vars += f'\n            "RUST_BACKTRACE=0",'
+
+                cml.write(
+                    self.CML_TEMPLATE.format(env_vars=env_vars, exe_name=exe_name)
+                )
+
+            log("Compiling CML...")
+
+            subprocess.check_call(
+                [
+                    self.tool_path("cmc"),
+                    "compile",
+                    cml_path,
+                    "--includepath",
+                    ".",
+                    "--output",
+                    cm_path,
+                ],
+                stdout=log_file,
+                stderr=log_file,
+            )
+
+            log("Writing manifest...")
+
+            # Write, build, and archive manifest
+            with open(manifest_path, "w", encoding="utf-8") as manifest:
+                manifest.write(
+                    self.MANIFEST_TEMPLATE.format(
+                        bin_path=bin_path,
+                        exe_name=exe_name,
+                        package_dir=package_dir,
+                        package_name=package_name,
+                        rust_dir=self.rust_dir,
+                        rustlib_dir=self.rustlib_dir(),
+                        sdk_dir=self.sdk_dir,
+                        libstd_name=self.libstd_name,
+                        libtest_name=self.libtest_name,
+                        target_arch=self.target_arch,
+                    )
+                )
+                for shared_lib in shared_libs:
+                    manifest.write(f"lib/{os.path.basename(shared_lib)}={shared_lib}\n")
+
+            log("Compiling and archiving manifest...")
+
+            subprocess.check_call(
+                [
+                    self.tool_path("pm"),
+                    "-o",
+                    package_dir,
+                    "-m",
+                    manifest_path,
+                    "build",
+                ],
+                stdout=log_file,
+                stderr=log_file,
+            )
+            subprocess.check_call(
+                [
+                    self.tool_path("pm"),
+                    "-o",
+                    package_dir,
+                    "-m",
+                    manifest_path,
+                    "archive",
+                ],
+                stdout=log_file,
+                stderr=log_file,
+            )
+
+            log("Publishing package to repo...")
+
+            # Publish package to repo
+            subprocess.check_call(
+                [
+                    self.tool_path("pm"),
+                    "publish",
+                    "-a",
+                    "-repo",
+                    self.repo_dir(),
+                    "-f",
+                    far_path,
+                ],
+                stdout=log_file,
+                stderr=log_file,
+            )
+
+            log("Running ffx test...")
+
+            # Run test on emulator
+            subprocess.run(
+                [
+                    self.tool_path("ffx"),
+                    "--config",
+                    self.ffx_user_config_path(),
+                    "test",
+                    "run",
+                    f"fuchsia-pkg://{self.TEST_REPO_NAME}/{package_name}#meta/{package_name}.cm",
+                    "--min-severity-logs",
+                    "TRACE",
+                    "--output-directory",
+                    test_output_dir,
+                    "--",
+                ]
+                + arguments,
+                env=self.ffx_cmd_env(),
+                check=False,
+                stdout=log_file,
+                stderr=log_file,
+            )
+
+            log("Reporting test suite output...")
+
+            # Read test suite output
+            run_summary_path = os.path.join(test_output_dir, "run_summary.json")
+            if os.path.exists(run_summary_path):
+                with open(run_summary_path, encoding="utf-8") as f:
+                    run_summary = json.loads(f.read())
+
+                suite = run_summary["data"]["suites"][0]
+                case = suite["cases"][0]
+
+                return_code = 0 if case["outcome"] == "PASSED" else 1
+
+                artifacts = case["artifacts"]
+                artifact_dir = case["artifact_dir"]
+                stdout_path = None
+                stderr_path = None
+
+                for path, artifact in artifacts.items():
+                    artifact_path = os.path.join(test_output_dir, artifact_dir, path)
+                    artifact_type = artifact["artifact_type"]
+
+                    if artifact_type == "STDERR":
+                        stderr_path = artifact_path
+                    elif artifact_type == "STDOUT":
+                        stdout_path = artifact_path
+
+                if stdout_path is not None and os.path.exists(stdout_path):
+                    with open(stdout_path, encoding="utf-8") as f:
+                        print(f.read(), file=sys.stdout, end="")
+
+                if stderr_path is not None and os.path.exists(stderr_path):
+                    with open(stderr_path, encoding="utf-8") as f:
+                        print(f.read(), file=sys.stderr, end="")
+            else:
+                log("Failed to open test run summary")
+                return_code = 254
+
+            log("Done!")
+
+        return return_code
+
+    def stop(self):
+        """Shuts down and cleans up the testing environment.
+
+        Args:
+        args: The command-line arguments to this command.
+        Returns:
+        The return code of the test (0 for success, else failure).
+
+        During cleanup, this function will stop the emulator, package server, and
+        update server, then delete all temporary files. If an error is encountered
+        while stopping any running processes, the temporary files will not be deleted.
+        Passing --delete-tmp will force the process to delete the files anyway.
+        """
+
+        self.log_debug("Reporting logs...")
+
+        # Print test log files
+        for test_dir in os.listdir(self.output_dir()):
+            log_path = os.path.join(self.output_dir(), test_dir, "log")
+            self.log_debug(f"\n---- Logs for test '{test_dir}' ----\n")
+            if os.path.exists(log_path):
+                with open(log_path, encoding="utf-8") as log:
+                    self.log_debug(log.read())
+            else:
+                self.log_debug("No logs found")
+
+        # Print the emulator log
+        self.log_debug("\n---- Emulator logs ----\n")
+        if os.path.exists(self.emulator_log_path()):
+            with open(self.emulator_log_path(), encoding="utf-8") as log:
+                self.log_debug(log.read())
+        else:
+            self.log_debug("No emulator logs found")
+
+        # Print the package server log
+        self.log_debug("\n---- Package server log ----\n")
+        if os.path.exists(self.package_server_log_path()):
+            with open(self.package_server_log_path(), encoding="utf-8") as log:
+                self.log_debug(log.read())
+        else:
+            self.log_debug("No package server log found")
+
+        # Print the ffx daemon log
+        self.log_debug("\n---- ffx daemon log ----\n")
+        if os.path.exists(self.ffx_daemon_log_path()):
+            with open(self.ffx_daemon_log_path(), encoding="utf-8") as log:
+                self.log_debug(log.read())
+        else:
+            self.log_debug("No ffx daemon log found")
+
+        # Stop package server
+        self.log_info("Stopping package server...")
+        os.kill(self.package_server_pid, signal.SIGTERM)
+
+        # Shut down the emulator
+        self.log_info("Stopping emulator...")
+        subprocess.check_call(
+            [
+                self.tool_path("fvdl"),
+                "--sdk",
+                "kill",
+                "--launched-proto",
+                self.vdl_output_path(),
+            ],
+            stdout=self.subprocess_output(),
+            stderr=self.subprocess_output(),
+        )
+
+        # Stop ffx isolation
+        self.log_info("Stopping ffx isolation...")
+        self.stop_ffx_isolation()
+
+    def delete_tmp(self):
+        # Remove temporary files
+        self.log_info("Deleting temporary files...")
+        shutil.rmtree(self.tmp_dir(), ignore_errors=True)
+
+    def debug(self, args):
+        command = [
+            self.tool_path("ffx"),
+            "--config",
+            self.ffx_user_config_path(),
+            "debug",
+            "connect",
+            "--",
+            "--build-id-dir",
+            os.path.join(self.sdk_dir, ".build-id"),
+            "--build-id-dir",
+            os.path.join(self.libs_dir(), ".build-id"),
+        ]
+
+        # Add rust source if it's available
+        if args.rust_src is not None:
+            command += [
+                "--build-dir",
+                args.rust_src,
+            ]
+
+        # Add fuchsia source if it's available
+        if args.fuchsia_src is not None:
+            command += [
+                "--build-dir",
+                os.path.join(args.fuchsia_src, "out", "default"),
+            ]
+
+        # Load debug symbols for the test binary and automatically attach
+        if args.test is not None:
+            if args.rust_src is None:
+                raise Exception(
+                    "A Rust source path is required with the `test` argument"
+                )
+
+            test_name = os.path.splitext(os.path.basename(args.test))[0]
+
+            build_dir = os.path.join(
+                args.rust_src,
+                "fuchsia-build",
+                self.host_arch_triple(),
+            )
+            test_dir = os.path.join(
+                build_dir,
+                "test",
+                os.path.dirname(args.test),
+                test_name,
+            )
+
+            with open(self.zxdb_script_path(), mode="w", encoding="utf-8") as f:
+                print(f"attach {test_name[:31]}", file=f)
+
+            command += [
+                "--symbol-path",
+                test_dir,
+                "-S",
+                self.zxdb_script_path(),
+            ]
+
+        # Add any other zxdb arguments the user passed
+        if args.zxdb_args is not None:
+            command += args.zxdb_args
+
+        # Connect to the running emulator with zxdb
+        subprocess.run(command, env=self.ffx_cmd_env(), check=False)
+
+
+def start(args):
+    test_env = TestEnvironment.from_args(args)
+    test_env.start()
+    return 0
+
+
+def run(args):
+    test_env = TestEnvironment.read_from_file()
+    return test_env.run(args)
+
+
+def stop(args):
+    test_env = TestEnvironment.read_from_file()
+    test_env.stop()
+    if not args.no_delete:
+        test_env.delete_tmp()
+    return 0
+
+
+def delete_tmp(args):
+    del args
+    test_env = TestEnvironment.read_from_file()
+    test_env.delete_tmp()
+    return 0
+
+
+def debug(args):
+    test_env = TestEnvironment.read_from_file()
+    test_env.debug(args)
+    return 0
+
+
+def main():
+    parser = argparse.ArgumentParser()
+
+    def print_help(args):
+        del args
+        parser.print_help()
+        return 0
+
+    parser.set_defaults(func=print_help)
+
+    subparsers = parser.add_subparsers(help="valid sub-commands")
+
+    start_parser = subparsers.add_parser(
+        "start", help="initializes the testing environment"
+    )
+    start_parser.add_argument(
+        "--rust",
+        help="the directory of the installed Rust compiler for Fuchsia",
+        required=True,
+    )
+    start_parser.add_argument(
+        "--sdk",
+        help="the directory of the fuchsia SDK",
+        required=True,
+    )
+    start_parser.add_argument(
+        "--verbose",
+        help="prints more output from executed processes",
+        action="store_true",
+    )
+    start_parser.add_argument(
+        "--target-arch",
+        help="the architecture of the image to test",
+        required=True,
+    )
+    start_parser.set_defaults(func=start)
+
+    run_parser = subparsers.add_parser(
+        "run", help="run a test in the testing environment"
+    )
+    run_parser.add_argument(
+        "n", help="the number of shared libs passed along with the executable", type=int
+    )
+    run_parser.add_argument("bin_path", help="path to the binary to run")
+    run_parser.add_argument(
+        "shared_libs",
+        help="the shared libs passed along with the binary",
+        nargs=argparse.REMAINDER,
+    )
+    run_parser.set_defaults(func=run)
+
+    stop_parser = subparsers.add_parser(
+        "stop", help="shuts down and cleans up the testing environment"
+    )
+    stop_parser.add_argument(
+        "--no-delete",
+        default=False,
+        action="store_true",
+        help="don't delete temporary files after stopping",
+    )
+    stop_parser.set_defaults(func=stop)
+
+    delete_parser = subparsers.add_parser(
+        "delete-tmp",
+        help="deletes temporary files after the testing environment has been manually cleaned up",
+    )
+    delete_parser.set_defaults(func=delete_tmp)
+
+    debug_parser = subparsers.add_parser(
+        "debug",
+        help="connect to the active testing environment with zxdb",
+    )
+    debug_parser.add_argument(
+        "--rust-src",
+        default=None,
+        help="the path to the Rust source being tested",
+    )
+    debug_parser.add_argument(
+        "--fuchsia-src",
+        default=None,
+        help="the path to the Fuchsia source",
+    )
+    debug_parser.add_argument(
+        "--test",
+        default=None,
+        help="the path to the test to debug (e.g. ui/box/new.rs)",
+    )
+    debug_parser.add_argument(
+        "zxdb_args",
+        default=None,
+        nargs=argparse.REMAINDER,
+        help="any additional arguments to pass to zxdb",
+    )
+    debug_parser.set_defaults(func=debug)
+
+    args = parser.parse_args()
+    return args.func(args)
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/src/ci/run.sh b/src/ci/run.sh
index 9d98ce224..7de06ec35 100755
--- a/src/ci/run.sh
+++ b/src/ci/run.sh
@@ -69,11 +69,6 @@ RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set rust.codegen-units-std=1"
 # space required for CI artifacts.
 RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --dist-compression-formats=xz"
 
-# Enable the `c` feature for compiler_builtins, but only when the `compiler-rt` source is available.
-if [ "$EXTERNAL_LLVM" = "" ]; then
-  RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set build.optimized-compiler-builtins"
-fi
-
 if [ "$DIST_SRC" = "" ]; then
   RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --disable-dist-src"
 fi
@@ -128,6 +123,10 @@ else
   # (And PGO is its own can of worms).
   if [ "$NO_DOWNLOAD_CI_LLVM" = "" ]; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.download-ci-llvm=if-available"
+  else
+    # When building for CI we want to use the static C++ Standard library
+    # included with LLVM, since a dynamic libstdcpp may not be available.
+    RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set llvm.static-libstdcpp"
   fi
 fi
 
diff --git a/src/ci/scripts/checkout-submodules.sh b/src/ci/scripts/checkout-submodules.sh
index f6cb8f8a6..5bb343241 100755
--- a/src/ci/scripts/checkout-submodules.sh
+++ b/src/ci/scripts/checkout-submodules.sh
@@ -36,7 +36,8 @@ function fetch_github_commit_archive {
     rm $cached
 }
 
-included="src/llvm-project src/doc/book src/doc/rust-by-example"
+#included="src/llvm-project src/doc/book src/doc/rust-by-example"
+included=""
 modules="$(git config --file .gitmodules --get-regexp '\.path$' | cut -d' ' -f2)"
 modules=($modules)
 use_git=""
@@ -60,9 +61,9 @@ done
 retry sh -c "git submodule deinit -f $use_git && \
     git submodule sync && \
     git submodule update -j 16 --init --recursive --depth 1 $use_git"
-STATUS=0
-for pid in ${bg_pids[*]}
-do
-    wait $pid || STATUS=1
-done
-exit ${STATUS}
+#STATUS=0
+#for pid in ${bg_pids[*]}
+#do
+#    wait $pid || STATUS=1
+#done
+#exit ${STATUS}