1.70.0: ui test failures due to "the full type name has been written to"

[xry111]

Three ui tests fail with 1.70.0 and channel = "stable":

[ui] tests/ui/mismatched_types/issue-36053-2.rs
[ui] tests/ui/typeck/issue-31173.rs
[ui] tests/ui/methods/method-not-found-generic-arg-elision.rs

They seem caused by the extra lines like:

= note: the full type name has been written to '$TEST_BUILD_DIR/methods/method-not-found-generic-arg-elision/method-not-found-generic-arg-elision.long-type-9165007450593903927.txt'

Should we suppress the "full type name output" within the test suite, or am I doing something wrong?

[TimNN]

Some background:

I've attempted to fix this in #105924 by enabling path remapping in UI tests by default.

However, that caused some usability regressions for rustc developers (#109725), so now this logic only triggers on CI: #110115

[jyn514]

i wonder if this should be an explicit config instead of being auto detected based on a CI environment variable. then we could enable it by default for the dev channel and disable it everywhere else.

[TimNN]

Having an explicit config for this sounds great. It would also mean that people with custom buildbots no longer need to spoof the CI detection logic (like e.g. Chromium does right now: chromium/chromium@9fc3ea5).

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-low

[chenyukang]

The path remapping is removed in #114090, I verified the test issue in the stable channel is fixed, closing this issue now.