Closed
Description
auto-reduced (treereduce-rust):
fn bug<T>() -> impl Iterator<
Item = [(); {
|found: &String| Some(false);
4
}],
> {
std::iter::empty()
}
fn main() {}
original:
#![allow(unused_must_use)]
fn bug<T>() -> impl Iterator<Item = [(); { |found: &String| Some(false); 4 }]> {
std::iter::empty()
}
fn ok<T>() -> Box<dyn Iterator<Item = [(); { |x: u32| { x }; 4 }]>> {
Box::new(std::iter::empty())
}
fn main() {
for _item in ok::<u32>() {}
for _item in bug::<u32>() {}
}Version information
rustc 1.81.0-nightly (acb62737a 2024-06-23)
binary: rustc
commit-hash: acb62737aca7045f331e7a05adc38bed213e278d
commit-date: 2024-06-23
host: x86_64-unknown-linux-gnu
release: 1.81.0-nightly
LLVM version: 18.1.7
Command:
/home/matthias/.rustup/toolchains/master/bin/rustc -Zincremental-verify-ich=yes -Cincremental=<dir> -Cdebuginfo=2
Program output
warning: unused variable: `found`
--> /tmp/icemaker_global_tempdir.fh96CiIOsxK3/rustc_testrunner_tmpdir_reporting.U9ifJLvY9ftQ/mvce.rs:3:17
|
3 | |found: &String| Some(false);
| ^^^^^ help: if this is intentional, prefix it with an underscore: `_found`
|
= note: `#[warn(unused_variables)]` on by default
warning: function `bug` is never used
--> /tmp/icemaker_global_tempdir.fh96CiIOsxK3/rustc_testrunner_tmpdir_reporting.U9ifJLvY9ftQ/mvce.rs:1:4
|
1 | fn bug<T>() -> impl Iterator<
| ^^^
|
= note: `#[warn(dead_code)]` on by default
warning: unused closure that must be used
--> /tmp/icemaker_global_tempdir.fh96CiIOsxK3/rustc_testrunner_tmpdir_reporting.U9ifJLvY9ftQ/mvce.rs:3:16
|
3 | |found: &String| Some(false);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: closures are lazy and do nothing unless called
= note: `#[warn(unused_must_use)]` on by default
warning: 3 warnings emitted
note: no errors encountered even though delayed bugs were created
note: those delayed bugs will now be shown as internal compiler errors
error: internal compiler error: no def-id for fresh lifetime
--> /tmp/icemaker_global_tempdir.fh96CiIOsxK3/rustc_testrunner_tmpdir_reporting.U9ifJLvY9ftQ/mvce.rs:3:24
|
3 | |found: &String| Some(false);
| ^^^^^^^
|
note: delayed at compiler/rustc_ast_lowering/src/lib.rs:1650:30 - disabled backtrace
--> /tmp/icemaker_global_tempdir.fh96CiIOsxK3/rustc_testrunner_tmpdir_reporting.U9ifJLvY9ftQ/mvce.rs:3:24
|
3 | |found: &String| Some(false);
| ^^^^^^^
note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
note: please make sure that you have updated to the latest nightly
note: rustc 1.81.0-nightly (acb62737a 2024-06-23) running on x86_64-unknown-linux-gnu
note: compiler flags: -Z incremental-verify-ich=yes -C incremental=[REDACTED] -C debuginfo=2
query stack during panic:
end of query stack