Rollup merge of #146011 - estebank:lifetime-obligation-span, r=lcnr

Point at fn bound that introduced lifetime obligation The last note is new ``` error[E0597]: `c` does not live long enough --> $DIR/without-precise-captures-we-are-powerless.rs:19:20 | LL | fn simple<'a>(x: &'a i32) { | -- lifetime `'a` defined here ... LL | let c = async move || { println!("{}", *x); }; | - binding `c` declared here LL | outlives::<'a>(c()); | ---------------^--- | | | | | borrowed value does not live long enough | argument requires that `c` is borrowed for `'a` LL | outlives::<'a>(call_once(c)); LL | } | - `c` dropped here while still borrowed | note: requirement that `c` is borrowed for `'a` introduced here --> $DIR/without-precise-captures-we-are-powerless.rs:7:33 | LL | fn outlives<'a>(_: impl Sized + 'a) {} | ^^ ``` When encountering a `ConstraintCategory::Predicate` in a funtion call, point at the `Span` for that `Predicate` to explain where the lifetime obligation originates from. CC rust-lang/rust#55307.
2025-09-30 22:25:16 +10:00 · 2025-09-30 22:25:16 +10:00 · 1aa426b335
commit 1aa426b335
parent 97e2d3c579 c5313fed76
24 changed files with 258 additions and 32 deletions
--- a/compiler/rustc_borrowck/src/borrowck_errors.rs
+++ b/compiler/rustc_borrowck/src/borrowck_errors.rs
@ -426,7 +426,7 @@ impl<'infcx, 'tcx> crate::MirBorrowckCtxt<'_, 'infcx, 'tcx> {
    }

    pub(crate) fn path_does_not_live_long_enough(&self, span: Span, path: &str) -> Diag<'infcx> {
-        struct_span_code_err!(self.dcx(), span, E0597, "{} does not live long enough", path,)
+        struct_span_code_err!(self.dcx(), span, E0597, "{} does not live long enough", path)
    }

    pub(crate) fn cannot_return_reference_to_local(
@ -480,7 +480,7 @@ impl<'infcx, 'tcx> crate::MirBorrowckCtxt<'_, 'infcx, 'tcx> {
    }

    pub(crate) fn temporary_value_borrowed_for_too_long(&self, span: Span) -> Diag<'infcx> {
-        struct_span_code_err!(self.dcx(), span, E0716, "temporary value dropped while borrowed",)
+        struct_span_code_err!(self.dcx(), span, E0716, "temporary value dropped while borrowed")
    }
 }

--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@ -2992,6 +2992,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
        self.buffer_error(err);
    }

+    #[tracing::instrument(level = "debug", skip(self, explanation))]
    fn report_local_value_does_not_live_long_enough(
        &self,
        location: Location,
@ -3001,13 +3002,6 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
        borrow_spans: UseSpans<'tcx>,
        explanation: BorrowExplanation<'tcx>,
    ) -> Diag<'infcx> {
-        debug!(
-            "report_local_value_does_not_live_long_enough(\
-             {:?}, {:?}, {:?}, {:?}, {:?}\
-             )",
-            location, name, borrow, drop_span, borrow_spans
-        );
-
        let borrow_span = borrow_spans.var_or_use_path_span();
        if let BorrowExplanation::MustBeValidFor {
            category,
--- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
@ -416,6 +416,26 @@ impl<'tcx> BorrowExplanation<'tcx> {
                {
                    self.add_object_lifetime_default_note(tcx, err, unsize_ty);
                }
+
+                let mut preds = path
+                    .iter()
+                    .filter_map(|constraint| match constraint.category {
+                        ConstraintCategory::Predicate(pred) if !pred.is_dummy() => Some(pred),
+                        _ => None,
+                    })
+                    .collect::<Vec<Span>>();
+                preds.sort();
+                preds.dedup();
+                if !preds.is_empty() {
+                    let s = if preds.len() == 1 { "" } else { "s" };
+                    err.span_note(
+                        preds,
+                        format!(
+                            "requirement{s} that the value outlives `{region_name}` introduced here"
+                        ),
+                    );
+                }
+
                self.add_lifetime_bound_suggestion_to_diagnostic(err, &category, span, region_name);
            }
            _ => {}
--- a/tests/ui/async-await/async-closures/without-precise-captures-we-are-powerless.rs
+++ b/tests/ui/async-await/async-closures/without-precise-captures-we-are-powerless.rs
@ -44,4 +44,18 @@ fn through_field_and_ref_move<'a>(x: &S<'a>) {
    outlives::<'a>(call_once(c)); //~ ERROR explicit lifetime required in the type of `x`
 }

+struct T;
+impl T {
+    fn outlives<'a>(&'a self, _: impl Sized + 'a) {}
+}
+fn through_method<'a>(x: &'a i32) {
+    let c = async || { println!("{}", *x); }; //~ ERROR `x` does not live long enough
+    T.outlives::<'a>(c());
+    T.outlives::<'a>(call_once(c));
+
+    let c = async move || { println!("{}", *x); };
+    T.outlives::<'a>(c()); //~ ERROR `c` does not live long enough
+    T.outlives::<'a>(call_once(c));
+}
+
 fn main() {}
--- a/tests/ui/async-await/async-closures/without-precise-captures-we-are-powerless.stderr
+++ b/tests/ui/async-await/async-closures/without-precise-captures-we-are-powerless.stderr
@ -28,6 +28,12 @@ LL |     outlives::<'a>(c());
 LL |     outlives::<'a>(call_once(c));
 LL | }
   | - `c` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'a` introduced here
+  --> $DIR/without-precise-captures-we-are-powerless.rs:7:33
+   |
+LL | fn outlives<'a>(_: impl Sized + 'a) {}
+   |                                 ^^

 error[E0597]: `x` does not live long enough
  --> $DIR/without-precise-captures-we-are-powerless.rs:26:13
@ -73,6 +79,12 @@ LL |     outlives::<'a>(c());
 LL |     outlives::<'a>(call_once(c));
 LL | }
   | - `c` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'a` introduced here
+  --> $DIR/without-precise-captures-we-are-powerless.rs:7:33
+   |
+LL | fn outlives<'a>(_: impl Sized + 'a) {}
+   |                                 ^^

 error[E0505]: cannot move out of `c` because it is borrowed
  --> $DIR/without-precise-captures-we-are-powerless.rs:32:30
@ -89,6 +101,12 @@ LL |     outlives::<'a>(c());
   |     argument requires that `c` is borrowed for `'a`
 LL |     outlives::<'a>(call_once(c));
   |                              ^ move out of `c` occurs here
+   |
+note: requirement that the value outlives `'a` introduced here
+  --> $DIR/without-precise-captures-we-are-powerless.rs:7:33
+   |
+LL | fn outlives<'a>(_: impl Sized + 'a) {}
+   |                                 ^^

 error[E0597]: `x` does not live long enough
  --> $DIR/without-precise-captures-we-are-powerless.rs:36:13
@ -129,6 +147,12 @@ LL |     outlives::<'a>(c());
 LL |     outlives::<'a>(call_once(c));
 LL | }
   | - `c` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'a` introduced here
+  --> $DIR/without-precise-captures-we-are-powerless.rs:7:33
+   |
+LL | fn outlives<'a>(_: impl Sized + 'a) {}
+   |                                 ^^

 error[E0621]: explicit lifetime required in the type of `x`
  --> $DIR/without-precise-captures-we-are-powerless.rs:44:5
@ -141,7 +165,44 @@ help: add explicit lifetime `'a` to the type of `x`
 LL | fn through_field_and_ref_move<'a>(x: &'a S<'a>) {
   |                                       ++

-error: aborting due to 10 previous errors
+error[E0597]: `x` does not live long enough
+  --> $DIR/without-precise-captures-we-are-powerless.rs:52:13
+   |
+LL | fn through_method<'a>(x: &'a i32) {
+   |                   -- lifetime `'a` defined here
+LL |     let c = async || { println!("{}", *x); };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ borrowed value does not live long enough
+LL |     T.outlives::<'a>(c());
+LL |     T.outlives::<'a>(call_once(c));
+   |     ------------------------------ argument requires that `x` is borrowed for `'a`
+...
+LL | }
+   |  - `x` dropped here while still borrowed
+
+error[E0597]: `c` does not live long enough
+  --> $DIR/without-precise-captures-we-are-powerless.rs:57:22
+   |
+LL | fn through_method<'a>(x: &'a i32) {
+   |                   -- lifetime `'a` defined here
+...
+LL |     let c = async move || { println!("{}", *x); };
+   |         - binding `c` declared here
+LL |     T.outlives::<'a>(c());
+   |     -----------------^---
+   |     |                |
+   |     |                borrowed value does not live long enough
+   |     argument requires that `c` is borrowed for `'a`
+LL |     T.outlives::<'a>(call_once(c));
+LL | }
+   | - `c` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'a` introduced here
+  --> $DIR/without-precise-captures-we-are-powerless.rs:49:47
+   |
+LL |     fn outlives<'a>(&'a self, _: impl Sized + 'a) {}
+   |                                               ^^
+
+error: aborting due to 12 previous errors

 Some errors have detailed explanations: E0505, E0597, E0621.
 For more information about an error, try `rustc --explain E0505`.
--- a/tests/ui/borrowck/fn-item-check-type-params.stderr
+++ b/tests/ui/borrowck/fn-item-check-type-params.stderr
@ -27,6 +27,12 @@ LL |     want(&String::new(), extend_lt);
   |     |     |
   |     |     creates a temporary value which is freed while still in use
   |     argument requires that borrow lasts for `'static`
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/fn-item-check-type-params.rs:47:33
+   |
+LL |     fn want<I, O>(_: I, _: impl Fn(I) -> O) {}
+   |                                 ^^^^^^^^^^

 error[E0716]: temporary value dropped while borrowed
  --> $DIR/fn-item-check-type-params.rs:54:26
@ -36,6 +42,12 @@ LL |     let val = extend_lt(&String::from("blah blah blah"));
   |               |          |
   |               |          creates a temporary value which is freed while still in use
   |               argument requires that borrow lasts for `'static`
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/fn-item-check-type-params.rs:22:21
+   |
+LL |     (T, Option<U>): Displayable,
+   |                     ^^^^^^^^^^^

 error: aborting due to 4 previous errors

--- a/tests/ui/borrowck/implementation-not-general-enough-ice-133252.stderr
+++ b/tests/ui/borrowck/implementation-not-general-enough-ice-133252.stderr
@ -22,6 +22,12 @@ LL |         force_send(async_load(&not_static));
 ...
 LL |     }
   |     - `not_static` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'1` introduced here
+  --> $DIR/implementation-not-general-enough-ice-133252.rs:16:18
+   |
+LL | fn force_send<T: Send>(_: T) {}
+   |                  ^^^^

 error: aborting due to 2 previous errors

--- a/tests/ui/borrowck/issue-17545.stderr
+++ b/tests/ui/borrowck/issue-17545.stderr
@ -10,6 +10,9 @@ LL | |     ));
   | |      -- temporary value is freed at the end of this statement
   | |______|
   |        argument requires that borrow lasts for `'a`
+   |
+note: requirement that the value outlives `'a` introduced here
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL

 error: aborting due to 1 previous error

--- a/tests/ui/generic-associated-types/bugs/hrtb-implied-1.stderr
+++ b/tests/ui/generic-associated-types/bugs/hrtb-implied-1.stderr
@ -14,6 +14,11 @@ note: due to a current limitation of the type system, this implies a `'static` l
   |
 LL |     for<'a> I::Item<'a>: Debug,
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/hrtb-implied-1.rs:26:26
+   |
+LL |     for<'a> I::Item<'a>: Debug,
+   |                          ^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/impl-trait/precise-capturing/migration-note.rs
+++ b/tests/ui/impl-trait/precise-capturing/migration-note.rs
@ -32,6 +32,7 @@ fn needs_static() {
    //~| NOTE borrowed value does not live long enoug

    fn needs_static(_: impl Sized + 'static) {}
+    //~^ NOTE requirement that the value outlives `'static` introduced here
    needs_static(a);
    //~^ NOTE argument requires that `x` is borrowed for `'static`
 }
@ -79,6 +80,7 @@ fn needs_static_mut() {
    //~| NOTE borrowed value does not live long enough

    fn needs_static(_: impl Sized + 'static) {}
+    //~^ NOTE requirement that the value outlives `'static` introduced here
    needs_static(a);
    //~^ NOTE argument requires that `x` is borrowed for `'static`
 }
--- a/tests/ui/impl-trait/precise-capturing/migration-note.stderr
+++ b/tests/ui/impl-trait/precise-capturing/migration-note.stderr
@ -1,5 +1,5 @@
 error[E0597]: `x` does not live long enough
-  --> $DIR/migration-note.rs:182:17
+  --> $DIR/migration-note.rs:184:17
   |
 LL |     let x = vec![0];
   |         - binding `x` declared here
@ -50,6 +50,11 @@ LL |
 LL | }
   | - `x` dropped here while still borrowed
   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/migration-note.rs:34:37
+   |
+LL |     fn needs_static(_: impl Sized + 'static) {}
+   |                                     ^^^^^^^
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
  --> $DIR/migration-note.rs:29:13
   |
@ -61,7 +66,7 @@ LL | fn display_len<T>(x: &Vec<T>) -> impl Display + use<T> {
   |                                               ++++++++

 error[E0505]: cannot move out of `x` because it is borrowed
-  --> $DIR/migration-note.rs:48:8
+  --> $DIR/migration-note.rs:49:8
   |
 LL |     let x = vec![1];
   |         - binding `x` declared here
@ -76,7 +81,7 @@ LL | }
   | - borrow might be used here, when `a` is dropped and runs the destructor for type `impl std::fmt::Display`
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:43:13
+  --> $DIR/migration-note.rs:44:13
   |
 LL |     let a = display_len(&x);
   |             ^^^^^^^^^^^^^^^
@ -90,7 +95,7 @@ LL |     let a = display_len(&x.clone());
   |                           ++++++++

 error[E0499]: cannot borrow `x` as mutable more than once at a time
-  --> $DIR/migration-note.rs:66:5
+  --> $DIR/migration-note.rs:67:5
   |
 LL |     let a = display_len_mut(&mut x);
   |                             ------ first mutable borrow occurs here
@ -102,7 +107,7 @@ LL |     println!("{a}");
   |                - first borrow later used here
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:63:13
+  --> $DIR/migration-note.rs:64:13
   |
 LL |     let a = display_len_mut(&mut x);
   |             ^^^^^^^^^^^^^^^^^^^^^^^
@ -112,7 +117,7 @@ LL | fn display_len_mut<T>(x: &mut Vec<T>) -> impl Display + use<T> {
   |                                                       ++++++++

 error[E0597]: `x` does not live long enough
-  --> $DIR/migration-note.rs:76:29
+  --> $DIR/migration-note.rs:77:29
   |
 LL |     let mut x = vec![1];
   |         ----- binding `x` declared here
@ -126,8 +131,13 @@ LL |
 LL | }
   | - `x` dropped here while still borrowed
   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/migration-note.rs:82:37
+   |
+LL |     fn needs_static(_: impl Sized + 'static) {}
+   |                                     ^^^^^^^
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:76:13
+  --> $DIR/migration-note.rs:77:13
   |
 LL |     let a = display_len_mut(&mut x);
   |             ^^^^^^^^^^^^^^^^^^^^^^^
@ -137,7 +147,7 @@ LL | fn display_len_mut<T>(x: &mut Vec<T>) -> impl Display + use<T> {
   |                                                       ++++++++

 error[E0505]: cannot move out of `x` because it is borrowed
-  --> $DIR/migration-note.rs:95:8
+  --> $DIR/migration-note.rs:97:8
   |
 LL |     let mut x = vec![1];
   |         ----- binding `x` declared here
@ -152,7 +162,7 @@ LL | }
   | - borrow might be used here, when `a` is dropped and runs the destructor for type `impl std::fmt::Display`
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:90:13
+  --> $DIR/migration-note.rs:92:13
   |
 LL |     let a = display_len_mut(&mut x);
   |             ^^^^^^^^^^^^^^^^^^^^^^^
@ -166,7 +176,7 @@ LL |     let a = display_len_mut(&mut x.clone());
   |                                   ++++++++

 error[E0506]: cannot assign to `s.f` because it is borrowed
-  --> $DIR/migration-note.rs:115:5
+  --> $DIR/migration-note.rs:117:5
   |
 LL |     let a = display_field(&s.f);
   |                           ---- `s.f` is borrowed here
@ -178,7 +188,7 @@ LL |     println!("{a}");
   |                - borrow later used here
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:112:13
+  --> $DIR/migration-note.rs:114:13
   |
 LL |     let a = display_field(&s.f);
   |             ^^^^^^^^^^^^^^^^^^^
@ -188,7 +198,7 @@ LL | fn display_field<T: Copy + Display>(t: &T) -> impl Display + use<T> {
   |                                                            ++++++++

 error[E0506]: cannot assign to `s.f` because it is borrowed
-  --> $DIR/migration-note.rs:131:5
+  --> $DIR/migration-note.rs:133:5
   |
 LL |     let a = display_field(&mut s.f);
   |                           -------- `s.f` is borrowed here
@ -200,7 +210,7 @@ LL |     println!("{a}");
   |                - borrow later used here
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:128:13
+  --> $DIR/migration-note.rs:130:13
   |
 LL |     let a = display_field(&mut s.f);
   |             ^^^^^^^^^^^^^^^^^^^^^^^
@ -210,7 +220,7 @@ LL | fn display_field<T: Copy + Display>(t: &T) -> impl Display + use<T> {
   |                                                            ++++++++

 error[E0503]: cannot use `s.f` because it was mutably borrowed
-  --> $DIR/migration-note.rs:143:5
+  --> $DIR/migration-note.rs:145:5
   |
 LL |     let a = display_field(&mut s.f);
   |                           -------- `s.f` is borrowed here
@ -222,7 +232,7 @@ LL |     println!("{a}");
   |                - borrow later used here
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:140:13
+  --> $DIR/migration-note.rs:142:13
   |
 LL |     let a = display_field(&mut s.f);
   |             ^^^^^^^^^^^^^^^^^^^^^^^
@ -232,7 +242,7 @@ LL | fn display_field<T: Copy + Display>(t: &T) -> impl Display + use<T> {
   |                                                            ++++++++

 error[E0597]: `z.f` does not live long enough
-  --> $DIR/migration-note.rs:159:25
+  --> $DIR/migration-note.rs:161:25
   |
 LL |         let z = Z { f: vec![1] };
   |             - binding `z` declared here
@ -248,7 +258,7 @@ LL | }
   |
   = note: values in a scope are dropped in the opposite order they are defined
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:159:13
+  --> $DIR/migration-note.rs:161:13
   |
 LL |         x = display_len(&z.f);
   |             ^^^^^^^^^^^^^^^^^
@ -258,7 +268,7 @@ LL | fn display_len<T>(x: &Vec<T>) -> impl Display + use<T> {
   |                                               ++++++++

 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/migration-note.rs:170:40
+  --> $DIR/migration-note.rs:172:40
   |
 LL |     let x = { let x = display_len(&mut vec![0]); x };
   |                                        ^^^^^^^ - - borrow later used here
@ -268,7 +278,7 @@ LL |     let x = { let x = display_len(&mut vec![0]); x };
   |
   = note: consider using a `let` binding to create a longer lived value
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:170:23
+  --> $DIR/migration-note.rs:172:23
   |
 LL |     let x = { let x = display_len(&mut vec![0]); x };
   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^
@ -279,7 +289,7 @@ LL | fn display_len<T>(x: &Vec<T>) -> impl Display + use<T> {
   |                                               ++++++++

 error[E0505]: cannot move out of `x` because it is borrowed
-  --> $DIR/migration-note.rs:198:10
+  --> $DIR/migration-note.rs:200:10
   |
 LL |     let x = String::new();
   |         - binding `x` declared here
@ -294,12 +304,12 @@ LL | }
   | - borrow might be used here, when `y` is dropped and runs the destructor for type `impl Sized`
   |
 note: this call may capture more lifetimes than intended, because Rust 2024 has adjusted the `impl Trait` lifetime capture rules
-  --> $DIR/migration-note.rs:195:13
+  --> $DIR/migration-note.rs:197:13
   |
 LL |     let y = capture_apit(&x);
   |             ^^^^^^^^^^^^^^^^
 note: you could use a `use<...>` bound to explicitly specify captures, but argument-position `impl Trait`s are not nameable
-  --> $DIR/migration-note.rs:189:21
+  --> $DIR/migration-note.rs:191:21
   |
 LL | fn capture_apit(x: &impl Sized) -> impl Sized {}
   |                     ^^^^^^^^^^
--- a/tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
+++ b/tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr
@ -69,6 +69,12 @@ LL |         cell_x.set(cell_a.get()); // forces 'a: 'x, implies 'a = 'static ->
 LL |     })
 LL | }
   | - `a` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/propagate-approximated-shorter-to-static-comparing-against-free.rs:13:8
+   |
+LL |     F: for<'x> FnOnce(Cell<&'a u32>, Cell<&'x u32>),
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 error: aborting due to 2 previous errors

--- a/tests/ui/nll/closure-requirements/propagate-multiple-requirements.stderr
+++ b/tests/ui/nll/closure-requirements/propagate-multiple-requirements.stderr
@ -13,6 +13,12 @@ LL |         z = &local_arr;
 ...
 LL | }
   | - `local_arr` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/propagate-multiple-requirements.rs:4:21
+   |
+LL | fn once<S, T, U, F: FnOnce(S, T) -> U>(f: F, s: S, t: T) -> U {
+   |                     ^^^^^^^^^^^^^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/nll/local-outlives-static-via-hrtb.stderr
+++ b/tests/ui/nll/local-outlives-static-via-hrtb.stderr
@ -17,6 +17,11 @@ note: due to a current limitation of the type system, this implies a `'static` l
   |
 LL | fn assert_static_via_hrtb<G>(_: G) where for<'a> G: Outlives<'a> {}
   |                                          ^^^^^^^^^^^^^^^^^^^^^^^
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/local-outlives-static-via-hrtb.rs:15:53
+   |
+LL | fn assert_static_via_hrtb<G>(_: G) where for<'a> G: Outlives<'a> {}
+   |                                                     ^^^^^^^^^^^^

 error[E0597]: `local` does not live long enough
  --> $DIR/local-outlives-static-via-hrtb.rs:25:45
@ -37,6 +42,11 @@ note: due to a current limitation of the type system, this implies a `'static` l
   |
 LL |     for<'a> &'a T: Reference<AssociatedType = &'a ()>,
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/local-outlives-static-via-hrtb.rs:19:30
+   |
+LL |     for<'a> &'a T: Reference<AssociatedType = &'a ()>,
+   |                              ^^^^^^^^^^^^^^^^^^^^^^^

 error: aborting due to 2 previous errors

--- a/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.nll.stderr
+++ b/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.nll.stderr
@ -18,6 +18,11 @@ note: due to a current limitation of the type system, this implies a `'static` l
   |
 LL | fn bad<F: Fn(&()) -> &()>(_: F) {}
   |           ^^^^^^^^^^^^^^
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/location-insensitive-scopes-issue-117146.rs:20:22
+   |
+LL | fn bad<F: Fn(&()) -> &()>(_: F) {}
+   |                      ^^^

 error: implementation of `Fn` is not general enough
  --> $DIR/location-insensitive-scopes-issue-117146.rs:13:5
--- a/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.polonius.stderr
+++ b/tests/ui/nll/polonius/location-insensitive-scopes-issue-117146.polonius.stderr
@ -18,6 +18,11 @@ note: due to a current limitation of the type system, this implies a `'static` l
   |
 LL | fn bad<F: Fn(&()) -> &()>(_: F) {}
   |           ^^^^^^^^^^^^^^
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/location-insensitive-scopes-issue-117146.rs:20:22
+   |
+LL | fn bad<F: Fn(&()) -> &()>(_: F) {}
+   |                      ^^^

 error: implementation of `Fn` is not general enough
  --> $DIR/location-insensitive-scopes-issue-117146.rs:13:5
--- a/tests/ui/regions/multiple-sources-for-outlives-requirement.rs
+++ b/tests/ui/regions/multiple-sources-for-outlives-requirement.rs
@ -0,0 +1,11 @@
+fn outlives_indir<'a: 'b, 'b, T: 'a>(_x: T) {}
+//~^ NOTE: requirements that the value outlives `'b` introduced here
+
+fn foo<'b>() { //~ NOTE: lifetime `'b` defined here
+    outlives_indir::<'_, 'b, _>(&mut 1u32); //~ ERROR: temporary value dropped while borrowed
+    //~^ NOTE: argument requires that borrow lasts for `'b`
+    //~| NOTE: creates a temporary value which is freed while still in use
+    //~| NOTE: temporary value is freed at the end of this statement
+}
+
+fn main() {}
--- a/tests/ui/regions/multiple-sources-for-outlives-requirement.stderr
+++ b/tests/ui/regions/multiple-sources-for-outlives-requirement.stderr
@ -0,0 +1,20 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/multiple-sources-for-outlives-requirement.rs:5:38
+   |
+LL | fn foo<'b>() {
+   |        -- lifetime `'b` defined here
+LL |     outlives_indir::<'_, 'b, _>(&mut 1u32);
+   |     ---------------------------------^^^^-- temporary value is freed at the end of this statement
+   |     |                                |
+   |     |                                creates a temporary value which is freed while still in use
+   |     argument requires that borrow lasts for `'b`
+   |
+note: requirements that the value outlives `'b` introduced here
+  --> $DIR/multiple-sources-for-outlives-requirement.rs:1:23
+   |
+LL | fn outlives_indir<'a: 'b, 'b, T: 'a>(_x: T) {}
+   |                       ^^         ^^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0716`.
--- a/tests/ui/regions/regions-infer-proc-static-upvar.stderr
+++ b/tests/ui/regions/regions-infer-proc-static-upvar.stderr
@ -11,6 +11,12 @@ LL | |     });
   | |______- argument requires that `x` is borrowed for `'static`
 LL |   }
   |   - `x` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/regions-infer-proc-static-upvar.rs:4:19
+   |
+LL | fn foo<F:FnOnce()+'static>(_p: F) { }
+   |                   ^^^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/regions/regions-pattern-typing-issue-19552.stderr
+++ b/tests/ui/regions/regions-pattern-typing-issue-19552.stderr
@ -10,6 +10,12 @@ LL |         [ word ] => { assert_static(word); }
 LL |     }
 LL | }
   | - `line` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/regions-pattern-typing-issue-19552.rs:1:21
+   |
+LL | fn assert_static<T: 'static>(_t: T) {}
+   |                     ^^^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/static/static-lifetime-bound.stderr
+++ b/tests/ui/static/static-lifetime-bound.stderr
@ -10,6 +10,12 @@ LL |     f(&x);
   |     argument requires that `x` is borrowed for `'static`
 LL | }
   | - `x` dropped here while still borrowed
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/static-lifetime-bound.rs:1:10
+   |
+LL | fn f<'a: 'static>(_: &'a i32) {}
+   |          ^^^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/static/static-region-bound.stderr
+++ b/tests/ui/static/static-region-bound.stderr
@ -7,6 +7,12 @@ LL |     f(x);
   |     ---- argument requires that borrow lasts for `'static`
 LL | }
   | - temporary value is freed at the end of this statement
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/static-region-bound.rs:3:8
+   |
+LL | fn f<T:'static>(_: T) {}
+   |        ^^^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/wf/wf-in-where-clause-static.current.stderr
+++ b/tests/ui/wf/wf-in-where-clause-static.current.stderr
@ -6,6 +6,12 @@ LL |     let s = foo(&String::from("blah blah blah"));
   |             |    |
   |             |    creates a temporary value which is freed while still in use
   |             argument requires that borrow lasts for `'static`
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/wf-in-where-clause-static.rs:12:17
+   |
+LL |     &'static S: Static,
+   |                 ^^^^^^

 error: aborting due to 1 previous error

--- a/tests/ui/wf/wf-in-where-clause-static.next.stderr
+++ b/tests/ui/wf/wf-in-where-clause-static.next.stderr
@ -6,6 +6,12 @@ LL |     let s = foo(&String::from("blah blah blah"));
   |             |    |
   |             |    creates a temporary value which is freed while still in use
   |             argument requires that borrow lasts for `'static`
+   |
+note: requirement that the value outlives `'static` introduced here
+  --> $DIR/wf-in-where-clause-static.rs:12:17
+   |
+LL |     &'static S: Static,
+   |                 ^^^^^^

 error: aborting due to 1 previous error