Merging upstream version 1.66.0+dfsg1.

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

26 files changed, 188 insertions, 39 deletions

diff --git a/src/test/ui/nll/closure-malformed-projection-input-issue-102800.rs b/src/test/ui/nll/closure-malformed-projection-input-issue-102800.rs
new file mode 100644
index 000000000..25f47f5b6
--- /dev/null
+++ b/src/test/ui/nll/closure-malformed-projection-input-issue-102800.rs
@@ -0,0 +1,31 @@
+// Regression test for #102800
+//
+// Here we are generating higher-ranked region constraints when normalizing and relating closure
+// input types. Previously this was an ICE in the error path because we didn't register enough
+// diagnostic information to render the higher-ranked subtyping error.
+
+// check-fail
+
+trait Trait {
+    type Ty;
+}
+
+impl Trait for &'static () {
+    type Ty = ();
+}
+
+fn main() {
+    let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+    //~^ ERROR lifetime may not live long enough
+    //~| ERROR higher-ranked subtype error
+    //~| ERROR higher-ranked subtype error
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+    //~| ERROR implementation of `Trait` is not general enough
+}
diff --git a/src/test/ui/nll/closure-malformed-projection-input-issue-102800.stderr b/src/test/ui/nll/closure-malformed-projection-input-issue-102800.stderr
new file mode 100644
index 000000000..dbd5dabd1
--- /dev/null
+++ b/src/test/ui/nll/closure-malformed-projection-input-issue-102800.stderr
@@ -0,0 +1,104 @@
+error: lifetime may not live long enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^-^
+   |                                                ||
+   |                                                |has type `<&'1 () as Trait>::Ty`
+   |                                                requires that `'1` must outlive `'static`
+
+error: higher-ranked subtype error
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^
+
+error: higher-ranked subtype error
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:12
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:12
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:12
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:12
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: implementation of `Trait` is not general enough
+  --> $DIR/closure-malformed-projection-input-issue-102800.rs:18:48
+   |
+LL |     let _: for<'a> fn(<&'a () as Trait>::Ty) = |_| {};
+   |                                                ^^^^^^ implementation of `Trait` is not general enough
+   |
+   = note: `&'0 ()` must implement `Trait`, for any lifetime `'0`...
+   = note: ...but `Trait` is actually implemented for the type `&'static ()`
+
+error: aborting due to 12 previous errors
+
diff --git a/src/test/ui/nll/closure-requirements/escape-argument-callee.stderr b/src/test/ui/nll/closure-requirements/escape-argument-callee.stderr
index 59b848ea8..d2d26b23d 100644
--- a/src/test/ui/nll/closure-requirements/escape-argument-callee.stderr
+++ b/src/test/ui/nll/closure-requirements/escape-argument-callee.stderr
@@ -6,7 +6,7 @@ LL |         let mut closure = expect_sig(|p, y| *p = y);
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<'r, 's, 't0> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('t0) }) i32)),
+               for<'a, 'b, 'c> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('c) }) i32)),
                (),
            ]
 
diff --git a/src/test/ui/nll/closure-requirements/escape-argument.stderr b/src/test/ui/nll/closure-requirements/escape-argument.stderr
index ff4e8e590..6355d3295 100644
--- a/src/test/ui/nll/closure-requirements/escape-argument.stderr
+++ b/src/test/ui/nll/closure-requirements/escape-argument.stderr
@@ -6,7 +6,7 @@ LL |         let mut closure = expect_sig(|p, y| *p = y);
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) i32)),
+               for<'a, 'b> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) i32)),
                (),
            ]
 
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
index 0d94fca28..5f9724ce3 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr
@@ -6,7 +6,7 @@ LL |         |_outlives1, _outlives2, _outlives3, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) &'_#3r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>)),
+               for<'a, 'b> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) &'_#3r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#4r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr
index 435a53533..ec728ebd5 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-ref.stderr
@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('t0) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('t2) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrNamed('t3) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) u32>)),
+               for<'a, 'b, 'c, 'd, 'e, 'f> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('c) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('e) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrNamed('f) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
index 6aafbe42c..012933797 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
@@ -6,7 +6,7 @@ LL |     foo(cell, |cell_a, cell_x| {
    |
    = note: defining type: case1::{closure#0} with closure substs [
                i32,
-               for<'r> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>)),
+               for<'a> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>)),
                (),
            ]
 
@@ -36,7 +36,7 @@ LL |     foo(cell, |cell_a, cell_x| {
    |
    = note: defining type: case2::{closure#0} with closure substs [
                i32,
-               for<'r> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>)),
+               for<'a> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>)),
                (),
            ]
    = note: number of external vids: 2
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
index c95907ea7..ce85b20b3 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr
@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's, 't0, 't1, 't2> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('t0) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('t2) }) u32>)),
+               for<'a, 'b, 'c, 'd, 'e> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('c) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('e) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#2r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
index db58d9d6f..20c7967b7 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr
@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('t0) }) std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('t2) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrNamed('t3) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) u32>)),
+               for<'a, 'b, 'c, 'd, 'e, 'f> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('c) }) std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('e) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrNamed('f) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r
diff --git a/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr b/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr
index be5f1e5ef..f7db5ab1f 100644
--- a/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-approximated-val.stderr
@@ -6,7 +6,7 @@ LL |     establish_relationships(cell_a, cell_b, |outlives1, outlives2, x, y| {
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>)),
+               for<'a, 'b> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r
diff --git a/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr b/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr
index d18db97be..3488edc75 100644
--- a/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr
@@ -6,7 +6,7 @@ LL |         |_outlives1, _outlives2, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>)),
+               for<'a, 'b> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r
diff --git a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
index e6f88de4e..0dc2d0de9 100644
--- a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr
@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's, 't0, 't1, 't2> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('t0) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('t2) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>)),
+               for<'a, 'b, 'c, 'd, 'e> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('c) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('e) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#2r
diff --git a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
index 5f5fce771..4c9e026ea 100644
--- a/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
+++ b/src/test/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr
@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<'r, 's, 't0, 't1, 't2, 't3> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('t0) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('t2) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrNamed('t3) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('t1) }) u32>)),
+               for<'a, 'b, 'c, 'd, 'e, 'f> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrNamed('c) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrNamed('e) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrNamed('f) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrNamed('d) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r
diff --git a/src/test/ui/nll/closure-requirements/return-wrong-bound-region.stderr b/src/test/ui/nll/closure-requirements/return-wrong-bound-region.stderr
index da89071ea..68429142e 100644
--- a/src/test/ui/nll/closure-requirements/return-wrong-bound-region.stderr
+++ b/src/test/ui/nll/closure-requirements/return-wrong-bound-region.stderr
@@ -6,7 +6,7 @@ LL |     expect_sig(|a, b| b); // ought to return `a`
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) i32)) -> &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) i32,
+               for<'a, 'b> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) i32)) -> &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) i32,
                (),
            ]
 
diff --git a/src/test/ui/nll/closures-in-loops.stderr b/src/test/ui/nll/closures-in-loops.stderr
index 2be0460df..1c1a31d35 100644
--- a/src/test/ui/nll/closures-in-loops.stderr
+++ b/src/test/ui/nll/closures-in-loops.stderr
@@ -13,17 +13,21 @@ error[E0499]: cannot borrow `x` as mutable more than once at a time
   --> $DIR/closures-in-loops.rs:13:16
    |
 LL |         v.push(|| x = String::new());
-   |                ^^ - borrows occur due to use of `x` in closure
-   |                |
-   |                `x` was mutably borrowed here in the previous iteration of the loop
+   |         -------^^-------------------
+   |         |      |  |
+   |         |      |  borrows occur due to use of `x` in closure
+   |         |      `x` was mutably borrowed here in the previous iteration of the loop
+   |         first borrow used here, in later iteration of loop
 
 error[E0524]: two closures require unique access to `x` at the same time
   --> $DIR/closures-in-loops.rs:20:16
    |
 LL |         v.push(|| *x = String::new());
-   |                ^^ -- borrows occur due to use of `x` in closure
-   |                |
-   |                closures are constructed here in different iterations of loop
+   |         -------^^--------------------
+   |         |      |  |
+   |         |      |  borrows occur due to use of `x` in closure
+   |         |      closures are constructed here in different iterations of loop
+   |         first borrow used here, in later iteration of loop
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/nll/issue-48623-generator.stderr b/src/test/ui/nll/issue-48623-generator.stderr
index 70a83e46f..1b35165db 100644
--- a/src/test/ui/nll/issue-48623-generator.stderr
+++ b/src/test/ui/nll/issue-48623-generator.stderr
@@ -4,8 +4,8 @@ warning: unused generator that must be used
 LL |     move || { d; yield; &mut *r };
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: `#[warn(unused_must_use)]` on by default
    = note: generators are lazy and do nothing unless resumed
+   = note: `#[warn(unused_must_use)]` on by default
 
 warning: 1 warning emitted
 
diff --git a/src/test/ui/nll/issue-51191.stderr b/src/test/ui/nll/issue-51191.stderr
index 9f4e971f9..63ca6ae5c 100644
--- a/src/test/ui/nll/issue-51191.stderr
+++ b/src/test/ui/nll/issue-51191.stderr
@@ -7,8 +7,8 @@ LL |     fn bar(self: &mut Self) {
 LL |         (&mut self).bar();
    |         ----------------- recursive call site
    |
-   = note: `#[warn(unconditional_recursion)]` on by default
    = help: a `loop` may express intention better if this is on purpose
+   = note: `#[warn(unconditional_recursion)]` on by default
 
 error[E0596]: cannot borrow `self` as mutable, as it is not declared as mutable
   --> $DIR/issue-51191.rs:7:9
diff --git a/src/test/ui/nll/issue-57642-higher-ranked-subtype.stderr b/src/test/ui/nll/issue-57642-higher-ranked-subtype.stderr
index 0ae6b7c1d..6e96f40c0 100644
--- a/src/test/ui/nll/issue-57642-higher-ranked-subtype.stderr
+++ b/src/test/ui/nll/issue-57642-higher-ranked-subtype.stderr
@@ -1,11 +1,11 @@
-error[E0599]: the function or associated item `make_g` exists for fn pointer `for<'r> fn(&'r ())`, but its trait bounds were not satisfied
+error[E0599]: the function or associated item `make_g` exists for fn pointer `for<'a> fn(&'a ())`, but its trait bounds were not satisfied
   --> $DIR/issue-57642-higher-ranked-subtype.rs:31:25
    |
 LL |     let x = <fn (&())>::make_g();
-   |                         ^^^^^^ function or associated item cannot be called on `for<'r> fn(&'r ())` due to unsatisfied trait bounds
+   |                         ^^^^^^ function or associated item cannot be called on `for<'a> fn(&'a ())` due to unsatisfied trait bounds
    |
    = note: the following trait bounds were not satisfied:
-           `for<'r> fn(&'r ()): X`
+           `for<'a> fn(&'a ()): X`
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `X` defines an item `make_g`, perhaps you need to implement it
   --> $DIR/issue-57642-higher-ranked-subtype.rs:4:1
@@ -13,11 +13,11 @@ note: `X` defines an item `make_g`, perhaps you need to implement it
 LL | trait X {
    | ^^^^^^^
 
-error[E0599]: no function or associated item named `make_f` found for fn pointer `for<'r> fn(&'r ())` in the current scope
+error[E0599]: no function or associated item named `make_f` found for fn pointer `for<'a> fn(&'a ())` in the current scope
   --> $DIR/issue-57642-higher-ranked-subtype.rs:35:25
    |
 LL |     let x = <fn (&())>::make_f();
-   |                         ^^^^^^ function or associated item not found in `for<'r> fn(&'r ())`
+   |                         ^^^^^^ function or associated item not found in `for<'a> fn(&'a ())`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Y` defines an item `make_f`, perhaps you need to implement it
diff --git a/src/test/ui/nll/issue-97997.stderr b/src/test/ui/nll/issue-97997.stderr
index 78401bbf6..46440c021 100644
--- a/src/test/ui/nll/issue-97997.stderr
+++ b/src/test/ui/nll/issue-97997.stderr
@@ -4,7 +4,7 @@ error: implementation of `Foo` is not general enough
 LL |     <fn(&u8) as Foo>::ASSOC;
    |     ^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
    |
-   = note: `Foo` would have to be implemented for the type `for<'r> fn(&'r u8)`
+   = note: `Foo` would have to be implemented for the type `for<'a> fn(&'a u8)`
    = note: ...but `Foo` is actually implemented for the type `fn(&'0 u8)`, for some specific lifetime `'0`
 
 error: implementation of `Foo` is not general enough
@@ -13,7 +13,7 @@ error: implementation of `Foo` is not general enough
 LL |     <fn(&u8) as Foo>::ASSOC;
    |     ^^^^^^^^^^^^^^^^^^^^^^^ implementation of `Foo` is not general enough
    |
-   = note: `Foo` would have to be implemented for the type `for<'r> fn(&'r u8)`
+   = note: `Foo` would have to be implemented for the type `for<'a> fn(&'a u8)`
    = note: ...but `Foo` is actually implemented for the type `fn(&'0 u8)`, for some specific lifetime `'0`
 
 error: aborting due to 2 previous errors
diff --git a/src/test/ui/nll/match-cfg-fake-edges.stderr b/src/test/ui/nll/match-cfg-fake-edges.stderr
index 250aa482e..2d48a9142 100644
--- a/src/test/ui/nll/match-cfg-fake-edges.stderr
+++ b/src/test/ui/nll/match-cfg-fake-edges.stderr
@@ -9,6 +9,11 @@ LL |         _ if { x = 2; true } => 1,
 LL |         _ if {
 LL |             x;
    |             ^ `x` used here but it isn't initialized
+   |
+help: consider assigning a value
+   |
+LL |     let x = 0;
+   |           +++
 
 error[E0382]: use of moved value: `x`
   --> $DIR/match-cfg-fake-edges.rs:35:13
diff --git a/src/test/ui/nll/match-on-borrowed.stderr b/src/test/ui/nll/match-on-borrowed.stderr
index 664f36f69..32666529f 100644
--- a/src/test/ui/nll/match-on-borrowed.stderr
+++ b/src/test/ui/nll/match-on-borrowed.stderr
@@ -40,6 +40,11 @@ LL |     let n: Never;
    |         - binding declared here but left uninitialized
 LL |     match n {}
    |           ^ `n` used here but it isn't initialized
+   |
+help: consider assigning a value
+   |
+LL |     let n: Never = todo!();
+   |                  +++++++++
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr b/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
index 8c4737988..b945ffedd 100644
--- a/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
+++ b/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
@@ -4,7 +4,7 @@ error: implementation of `Y` is not general enough
 LL |     let _x = <fn(&())>::make_f();
    |              ^^^^^^^^^^^^^^^^^^^ implementation of `Y` is not general enough
    |
-   = note: `Y` would have to be implemented for the type `for<'r> fn(&'r ())`
+   = note: `Y` would have to be implemented for the type `for<'a> fn(&'a ())`
    = note: ...but `Y` is actually implemented for the type `fn(&'0 ())`, for some specific lifetime `'0`
 
 error: implementation of `Y` is not general enough
@@ -13,7 +13,7 @@ error: implementation of `Y` is not general enough
 LL |     let _x = <fn(&())>::make_f();
    |              ^^^^^^^^^^^^^^^^^^^ implementation of `Y` is not general enough
    |
-   = note: `Y` would have to be implemented for the type `for<'r> fn(&'r ())`
+   = note: `Y` would have to be implemented for the type `for<'a> fn(&'a ())`
    = note: ...but `Y` is actually implemented for the type `fn(&'0 ())`, for some specific lifetime `'0`
 
 error: implementation of `Y` is not general enough
@@ -22,7 +22,7 @@ error: implementation of `Y` is not general enough
 LL |     let _x = <fn(&())>::make_f();
    |              ^^^^^^^^^^^^^^^^^^^ implementation of `Y` is not general enough
    |
-   = note: `Y` would have to be implemented for the type `for<'r> fn(&'r ())`
+   = note: `Y` would have to be implemented for the type `for<'a> fn(&'a ())`
    = note: ...but `Y` is actually implemented for the type `fn(&'0 ())`, for some specific lifetime `'0`
 
 error: aborting due to 3 previous errors
diff --git a/src/test/ui/nll/relate_tys/universe-violation.stderr b/src/test/ui/nll/relate_tys/universe-violation.stderr
index 6f38154e3..fe801b42c 100644
--- a/src/test/ui/nll/relate_tys/universe-violation.stderr
+++ b/src/test/ui/nll/relate_tys/universe-violation.stderr
@@ -4,7 +4,7 @@ error[E0308]: mismatched types
 LL |     let b: fn(&u32) -> &u32 = a;
    |                               ^ one type is more general than the other
    |
-   = note: expected fn pointer `for<'r> fn(&'r u32) -> &'r u32`
+   = note: expected fn pointer `for<'a> fn(&'a u32) -> &'a u32`
               found fn pointer `fn(&u32) -> &u32`
 
 error: aborting due to previous error
diff --git a/src/test/ui/nll/trait-associated-constant.stderr b/src/test/ui/nll/trait-associated-constant.stderr
index ae0ffd904..cf1c52ba7 100644
--- a/src/test/ui/nll/trait-associated-constant.stderr
+++ b/src/test/ui/nll/trait-associated-constant.stderr
@@ -2,7 +2,7 @@ error[E0308]: const not compatible with trait
   --> $DIR/trait-associated-constant.rs:21:5
    |
 LL |     const AC: Option<&'c str> = None;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ lifetime mismatch
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ lifetime mismatch
    |
    = note: expected enum `Option<&'b str>`
               found enum `Option<&'c str>`
diff --git a/src/test/ui/nll/ty-outlives/impl-trait-captures.stderr b/src/test/ui/nll/ty-outlives/impl-trait-captures.stderr
index 330c6fafa..737cb3584 100644
--- a/src/test/ui/nll/ty-outlives/impl-trait-captures.stderr
+++ b/src/test/ui/nll/ty-outlives/impl-trait-captures.stderr
@@ -1,14 +1,14 @@
-error[E0700]: hidden type for `Opaque(DefId(0:11 ~ impl_trait_captures[1afc]::foo::{opaque#0}), [ReStatic, T, ReEarlyBound(0, 'a)])` captures lifetime that does not appear in bounds
+error[E0700]: hidden type for `Opaque(DefId(0:13 ~ impl_trait_captures[1afc]::foo::{opaque#0}), [ReStatic, T, ReEarlyBound(0, 'a)])` captures lifetime that does not appear in bounds
   --> $DIR/impl-trait-captures.rs:11:5
    |
 LL | fn foo<'a, T>(x: &T) -> impl Foo<'a> {
-   |                  -- hidden type `&ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:13 ~ impl_trait_captures[1afc]::foo::'_), '_)) T` captures the anonymous lifetime defined here
+   |                  -- hidden type `&ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:12 ~ impl_trait_captures[1afc]::foo::'_), '_)) T` captures the anonymous lifetime defined here
 LL |     x
    |     ^
    |
-help: to declare that the `impl Trait` captures `ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:13 ~ impl_trait_captures[1afc]::foo::'_), '_))`, you can add an explicit `ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:13 ~ impl_trait_captures[1afc]::foo::'_), '_))` lifetime bound
+help: to declare that `Opaque(DefId(0:13 ~ impl_trait_captures[1afc]::foo::{opaque#0}), [ReEarlyBound(0, 'a), T, ReEarlyBound(2, 'a)])` captures `ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:12 ~ impl_trait_captures[1afc]::foo::'_), '_))`, you can add an explicit `ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:12 ~ impl_trait_captures[1afc]::foo::'_), '_))` lifetime bound
    |
-LL | fn foo<'a, T>(x: &T) -> impl Foo<'a> + ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:13 ~ impl_trait_captures[1afc]::foo::'_), '_)) {
+LL | fn foo<'a, T>(x: &T) -> impl Foo<'a> + ReFree(DefId(0:8 ~ impl_trait_captures[1afc]::foo), BrNamed(DefId(0:12 ~ impl_trait_captures[1afc]::foo::'_), '_)) {
    |                                      ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 error: aborting due to previous error
diff --git a/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr b/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
index 5d9a044d1..61c7d2550 100644
--- a/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
+++ b/src/test/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr
@@ -6,7 +6,7 @@ LL |     twice(cell, value, |a, b| invoke(a, b));
    |
    = note: defining type: generic::<T>::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) T)),
+               for<'a, 'b> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) T)),
                (),
            ]
    = note: number of external vids: 2
@@ -28,7 +28,7 @@ LL |     twice(cell, value, |a, b| invoke(a, b));
    |
    = note: defining type: generic_fail::<T>::{closure#0} with closure substs [
                i16,
-               for<'r, 's> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('r) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('s) }) T)),
+               for<'a, 'b> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrNamed('a) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrNamed('b) }) T)),
                (),
            ]
    = note: late-bound region is '_#2r