2 files changed, 55 insertions, 0 deletions
diff --git a/hooks/no-merged-usr/essential00.sh b/hooks/no-merged-usr/essential00.sh
new file mode 120000
index 0000000..5360c8f
--- /dev/null
+++ b/hooks/no-merged-usr/essential00.sh
@@ -0,0 +1 @@
+../merged-usr/essential00.sh
+\ No newline at end of file
diff --git a/hooks/no-merged-usr/setup00.sh b/hooks/no-merged-usr/setup00.sh
new file mode 100755
index 0000000..df50499
--- /dev/null
+++ b/hooks/no-merged-usr/setup00.sh
@@ -0,0 +1,54 @@
+#!/bin/sh
+#
+# mmdebstrap does have a --no-merged-usr option but only as a no-op for
+# debootstrap compatibility
+#
+# Using this hook script, you can emulate what debootstrap does to set up
+# a system without merged-/usr even after the essential init-system-helpers
+# package added a dependency on "usrmerge | usr-is-merged". By installing
+# a dummy usr-is-merged package, it avoids pulling in the dependencies of
+# the usrmerge package.
+
+set -eu
+
+if [ "${MMDEBSTRAP_VERBOSITY:-1}" -ge 3 ]; then
+        set -x
+fi
+
+TARGET="$1"
+
+echo "Warning: starting with Debian 12 (Bookworm), systems without merged-/usr are not supported anymore" >&2
+echo "Warning: starting with Debian 13 (Trixie), merged-/usr symlinks are shipped by packages in the essential-set making this hook ineffective" >&2
+
+echo "this system will not be supported in the future" > "$TARGET/etc/unsupported-skip-usrmerge-conversion"
+
+# now install an empty "usr-is-merged" package to avoid installing the
+# usrmerge package on this system even after init-system-helpers starts
+# depending on "usrmerge | usr-is-merged".
+#
+# This package will not end up in the final chroot because the essential
+# hook replaces it with the actual usr-is-merged package from src:usrmerge.
+
+tmpdir=$(mktemp --directory --tmpdir="$TARGET/tmp")
+mkdir -p "$tmpdir/usr-is-merged/DEBIAN"
+
+cat << END > "$tmpdir/usr-is-merged/DEBIAN/control"
+Package: usr-is-merged
+Priority: optional
+Section: oldlibs
+Maintainer: Johannes Schauer Marin Rodrigues <josch@debian.org>
+Architecture: all
+Multi-Arch: foreign
+Source: mmdebstrap-dummy-usr-is-merged
+Version: 1
+Description: dummy package created by mmdebstrap no-merged-usr setup hook
+ This package was generated and installed by the mmdebstrap no-merged-usr
+ setup hook at /usr/share/mmdebstrap/hooks/no-merged-usr.
+ .
+ If this package is installed in the final chroot, then this is a bug
+ in mmdebstrap. Please report: https://gitlab.mister-muffin.de/josch/mmdebstrap
+END
+dpkg-deb --build "$tmpdir/usr-is-merged" "$tmpdir/usr-is-merged.deb"
+dpkg --root="$TARGET" --log="$TARGET/var/log/dpkg.log" --install "$tmpdir/usr-is-merged.deb"
+rm "$tmpdir/usr-is-merged.deb" "$tmpdir/usr-is-merged/DEBIAN/control"
+rmdir "$tmpdir/usr-is-merged/DEBIAN" "$tmpdir/usr-is-merged" "$tmpdir"