sysroot spans are not printed on some targets (affected: Debian, rust-lang's own i586; unaffected: Fedora)

[infinity0]

EDIT(@eddyb): For a detailed update/explanation, see #53081 (comment).

---

I'm trying to track down why we have this diff on all arches, which causes that test to fail:

Test, test output

29	   |
30	LL |     fn hash(&self, hasher: &mut impl Hasher) {}
31	   |                                 ^^^^^^^^^^^ expected generic parameter, found `impl Trait`
-	   | 
-	  ::: $SRC_DIR/libcore/hash/mod.rs:185:13
-	   |
-	LL |     fn hash<H: Hasher>(&self, state: &mut H);
-	   |             - declaration in trait here
37	
38	error: aborting due to 3 previous errors
39	

The test passes on Fedora.

Two main things we're doing differently in Debian is that we're currently using cargo 0.27 to build (rather than cargo 0.28) and we also omit some components. However I don't see why either of these should affect the above test output. I also can't see why our other patches should affect it.

[Dylan-DPC-zz]

@infinity0

The issue is not OS-dependent. The reason your build is failing is because the function signature in your implementation isn't matching the function in your trait definition.

[infinity0]

@Dylan-DPC

I think you're misunderstanding this bug report, this is part of a test (ui/impl-trait/impl-generic-mismatch) which tests that rustc correctly fails to compile invalid code. In Debian, this works fine, our rustc does indeed fail to compile the invalid code. However the problem is that the error message is missing some things. That's what the diff is about.

[infinity0]

Our const-size_of-cycle test also fails but passes in Fedora with a similar lack-of-error-details.

diff of stderr:

2	   |
3	note: ...which requires normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All }, value: [u8; _] }`...
4	note: ...which requires const-evaluating `Foo::bytes::{{constant}}`...
-	  --> $SRC_DIR/libcore/mem.rs:LL:COL
-	   |
-	LL |     intrinsics::size_of::<T>()
-	   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
9	   = note: ...which again requires computing layout of `Foo`, completing the cycle
10	note: cycle used when const-evaluating `Foo::bytes::{{constant}}`
-	  --> $SRC_DIR/libcore/mem.rs:LL:COL
-	   |
-	LL |     intrinsics::size_of::<T>()
-	   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
15	
16	error: aborting due to previous error
17	

[infinity0]

related: #54546

[infinity0]

Strangely, if I run rust's own upstream binary compiler from here the output is also missing error details.

$ rustc/bin/rustc -L$PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib ../const-size_of-cycle.rs
error[E0391]: cycle detected when computing layout of `Foo`
  |
note: ...which requires normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All }, value: [u8; _] }`...
note: ...which requires const-evaluating `Foo::bytes::{{constant}}`...
  = note: ...which again requires computing layout of `Foo`, completing the cycle
note: cycle used when const-evaluating `Foo::bytes::{{constant}}`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0391`.

[infinity0]

@oli-obk you created src/test/ui/impl-trait/impl-generic-mismatch.stderr in 00842d1, and @davidtwco you created src/test/ui/compile-fail-migration/const-size_of-cycle.stderr in b16a306, do either of you have any clues about these mismatching error messages?

[eddyb]

cc @michaelwoerister This looks like it might be related to file paths for libcore, not being found when running tests.

[infinity0]

FWIW here is the output with RUST_LOG=debug:

$ RUST_LOG=trace rustc/bin/rustc -L$PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib ../const-size_of-cycle.rs
 INFO $TS: jobserver::imp: created a jobserver: Client { read: File { fd: 3, path: "pipe:[57109581]", read: true, write: false }, write: File { fd: 4, path: "pipe:[57109581]", read: false, write: true } }
 INFO $TS: rustc_driver: codegen backend candidate: $PWD/rustc/lib/rustlib/x86_64-unknown-linux-gnu/codegen-backends
 INFO $TS: rustc_driver: probing $PWD/rustc/lib/rustlib/x86_64-unknown-linux-gnu/codegen-backends for a codegen backend
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate std as std`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-52f862a21e09568c.rlib
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-52f862a21e09568c.so
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-52f862a21e09568c.rlib
 INFO $TS: rustc_metadata::locator: reading "libstd-52f862a21e09568c.rlib" => 314.101µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate std as std`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-f2133e8b70369157.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-f2133e8b70369157.rlib
 INFO $TS: rustc_metadata::locator: reading "libcore-f2133e8b70369157.rlib" => 224.774µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-71671e8958739d51.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-71671e8958739d51.rlib
 INFO $TS: rustc_metadata::locator: reading "libcompiler_builtins-71671e8958739d51.rlib" => 167.677µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate alloc hash: `de32cde30cc6bc18` extra filename: `-2d44723f32308cf8`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate alloc as alloc`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-2d44723f32308cf8.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-2d44723f32308cf8.rlib
 INFO $TS: rustc_metadata::locator: reading "liballoc-2d44723f32308cf8.rlib" => 129.342µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate alloc as alloc`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate alloc_system hash: `20b374f02cf54767` extra filename: `-48c8a8552cff934e`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate alloc_system as alloc_system`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc_system-48c8a8552cff934e.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc_system-48c8a8552cff934e.rlib
 INFO $TS: rustc_metadata::locator: reading "liballoc_system-48c8a8552cff934e.rlib" => 54.302µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate alloc_system as alloc_system`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate libc hash: `e04f69583f78a1ba` extra filename: `-517830e9d56bab97`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate libc as libc`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-517830e9d56bab97.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-517830e9d56bab97.rlib
 INFO $TS: rustc_metadata::locator: reading "liblibc-517830e9d56bab97.rlib" => 81.651µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate libc as libc`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate libc hash: `e04f69583f78a1ba` extra filename: `-517830e9d56bab97`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate libc as libc`
 INFO $TS: rustc_metadata::creader: resolving dep crate unwind hash: `23d16d19bf235477` extra filename: `-4c9cbe622de116ab`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate unwind as unwind`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-4c9cbe622de116ab.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-4c9cbe622de116ab.rlib
 INFO $TS: rustc_metadata::locator: reading "libunwind-4c9cbe622de116ab.rlib" => 53.925µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate unwind as unwind`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate libc hash: `e04f69583f78a1ba` extra filename: `-517830e9d56bab97`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate libc as libc`
 INFO $TS: rustc_metadata::creader: resolving dep crate alloc_jemalloc hash: `e11976872a475adc` extra filename: `-a7f738f7aa980965`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate alloc_jemalloc as alloc_jemalloc`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc_jemalloc-a7f738f7aa980965.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc_jemalloc-a7f738f7aa980965.rlib
 INFO $TS: rustc_metadata::locator: reading "liballoc_jemalloc-a7f738f7aa980965.rlib" => 199.469µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate alloc_jemalloc as alloc_jemalloc`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate libc hash: `e04f69583f78a1ba` extra filename: `-517830e9d56bab97`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate libc as libc`
 INFO $TS: rustc_metadata::creader: resolving dep crate panic_unwind hash: `1dcbbefca552f7b5` extra filename: `-b89f1a9b548bfef9`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate panic_unwind as panic_unwind`
 INFO $TS: rustc_metadata::creader: falling back to a load
 INFO $TS: rustc_metadata::locator: lib candidate: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-b89f1a9b548bfef9.rlib
 INFO $TS: rustc_metadata::locator: rlib reading metadata from: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-b89f1a9b548bfef9.rlib
 INFO $TS: rustc_metadata::locator: reading "libpanic_unwind-b89f1a9b548bfef9.rlib" => 62.774µs
 INFO $TS: rustc_metadata::creader: register crate `extern crate panic_unwind as panic_unwind`
 INFO $TS: rustc_metadata::creader: resolving dep crate core hash: `af89e4eb0280bac6` extra filename: `-f2133e8b70369157`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate core as core`
 INFO $TS: rustc_metadata::creader: resolving dep crate compiler_builtins hash: `d04ac580e8a9e993` extra filename: `-71671e8958739d51`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate compiler_builtins as compiler_builtins`
 INFO $TS: rustc_metadata::creader: resolving dep crate alloc hash: `de32cde30cc6bc18` extra filename: `-2d44723f32308cf8`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate alloc as alloc`
 INFO $TS: rustc_metadata::creader: resolving dep crate libc hash: `e04f69583f78a1ba` extra filename: `-517830e9d56bab97`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate libc as libc`
 INFO $TS: rustc_metadata::creader: resolving dep crate unwind hash: `23d16d19bf235477` extra filename: `-4c9cbe622de116ab`
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate unwind as unwind`
 INFO $TS: rustc_driver::driver: 0 parse sess buffered_lints
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate alloc_jemalloc as alloc_jemalloc`
 INFO $TS: rustc_metadata::creader: injecting a dep from 1 to 9
 INFO $TS: rustc_metadata::creader: panic runtime not found -- loading panic_unwind
 INFO $TS: rustc_metadata::creader: resolving crate `extern crate panic_unwind as panic_unwind`
 INFO $TS: rustc_metadata::creader: injecting a dep from 1 to 9
 INFO $TS: rustc_metadata::creader: resolved crates:
 INFO $TS: rustc_metadata::creader:   name: std
 INFO $TS: rustc_metadata::creader:   cnum: 1
 INFO $TS: rustc_metadata::creader:   hash: 55e0028ad01a6c49
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:   dylib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-52f862a21e09568c.so
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-52f862a21e09568c.rlib
 INFO $TS: rustc_metadata::creader:   name: core
 INFO $TS: rustc_metadata::creader:   cnum: 2
 INFO $TS: rustc_metadata::creader:   hash: af89e4eb0280bac6
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-f2133e8b70369157.rlib
 INFO $TS: rustc_metadata::creader:   name: compiler_builtins
 INFO $TS: rustc_metadata::creader:   cnum: 3
 INFO $TS: rustc_metadata::creader:   hash: d04ac580e8a9e993
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-71671e8958739d51.rlib
 INFO $TS: rustc_metadata::creader:   name: alloc
 INFO $TS: rustc_metadata::creader:   cnum: 4
 INFO $TS: rustc_metadata::creader:   hash: de32cde30cc6bc18
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-2d44723f32308cf8.rlib
 INFO $TS: rustc_metadata::creader:   name: alloc_system
 INFO $TS: rustc_metadata::creader:   cnum: 5
 INFO $TS: rustc_metadata::creader:   hash: 20b374f02cf54767
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc_system-48c8a8552cff934e.rlib
 INFO $TS: rustc_metadata::creader:   name: libc
 INFO $TS: rustc_metadata::creader:   cnum: 6
 INFO $TS: rustc_metadata::creader:   hash: e04f69583f78a1ba
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-517830e9d56bab97.rlib
 INFO $TS: rustc_metadata::creader:   name: unwind
 INFO $TS: rustc_metadata::creader:   cnum: 7
 INFO $TS: rustc_metadata::creader:   hash: 23d16d19bf235477
 INFO $TS: rustc_metadata::creader:   reqd: Explicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-4c9cbe622de116ab.rlib
 INFO $TS: rustc_metadata::creader:   name: alloc_jemalloc
 INFO $TS: rustc_metadata::creader:   cnum: 8
 INFO $TS: rustc_metadata::creader:   hash: e11976872a475adc
 INFO $TS: rustc_metadata::creader:   reqd: Implicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc_jemalloc-a7f738f7aa980965.rlib
 INFO $TS: rustc_metadata::creader:   name: panic_unwind
 INFO $TS: rustc_metadata::creader:   cnum: 9
 INFO $TS: rustc_metadata::creader:   hash: 1dcbbefca552f7b5
 INFO $TS: rustc_metadata::creader:   reqd: Implicit
 INFO $TS: rustc_metadata::creader:    rlib: $PWD/rust-std-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-b89f1a9b548bfef9.rlib
error[E0391]: cycle detected when computing layout of `Foo`
  |
note: ...which requires normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All }, value: [u8; _] }`...
note: ...which requires const-evaluating `Foo::bytes::{{constant}}`...
  = note: ...which again requires computing layout of `Foo`, completing the cycle
note: cycle used when const-evaluating `Foo::bytes::{{constant}}`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0391`.

Hopefully it's easy to reproduce with rust-lang's own rustc binaries.

[infinity0]

@michaelwoerister would our usage of --remap-path-prefix during the build, be interfering with the tests? If I ln -s src/libcore libcore the compilation output now contains the extra error detail, but the test still fails because the paths are different:

[..]
10	note: cycle used when const-evaluating `Foo::bytes::{{constant}}`
-	  --> $SRC_DIR/libcore/mem.rs:LL:COL
+	  --> libcore/mem.rs:289:5
12	   |
[..]

$ strings ./build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-1361a4a303e9f67c.rlib | rg '/mem\.rs'
libcore/mem.rs
$ strings ./build/x86_64-unknown-linux-gnu/stage2/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-1361a4a303e9f67c.rlib | rg '/usr/src' | sort -u
/usr/src/rustc-1.31.0/src

[johnterickson]

I am able to repro this at will in my CI environment if anyone has suggestions on extra logging to add or data to collect.

[oli-obk]

I'm not sure what the correct action to resolve this issue is.

Is it to change our test suite so it stops showing code snippets from the standard library?