Recent regression on `test_tail::test_stdin_default stdout`

[sylvestre]

I guess it regressed by #3874

---- test_tail::test_stdin_default stdout ----
current_directory_resolved: 
open: /var/folders/24/8k48jl6d249_n_qfxwsl6xvm0000gn/T/.tmpG4rm0A/foobar.txt
run: /Users/runner/work/coreutils/coreutils/target/debug/coreutils tail
open: /var/folders/24/8k48jl6d249_n_qfxwsl6xvm0000gn/T/.tmpG4rm0A/foobar_stdin_default.expected
---- test_tail::test_stdin_default stderr ----
thread 'main' panicked at 'assertion failed: `(left == right)`

Diff < left / right > :
>dos
>tres
>quattro
>cinco
>seis
>siette
>ocho
>nueve
>diez
>once
>

', tests/common/util.rs:235:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace


failures:
    test_tail::test_stdin_default

cc @Joining7943
Full log:
https://github.com/uutils/coreutils/runs/8270803201?check_suite_focus=true

[Joining7943]

I'll have a look into it

[Joining7943]

Hmm, the other macos ci runs pass the same test. Maybe rerunning the ci tests would give some additional insight.

[sylvestre]

Similar issue in https://github.com/uutils/coreutils/runs/8273012666?check_suite_focus=true

---- test_tail::pipe_tests::test_pipe_when_lines_option_given_multibyte_utf8_characters stdout ----
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n +0
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n +2
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n +3
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n +4
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n +5
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n -4
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n -3
current_directory_resolved: 
run: /Users/runner/work/coreutils/coreutils/target/x86_64-apple-darwin/debug/coreutils tail -n -2
thread 'test_tail::pipe_tests::test_pipe_when_lines_option_given_multibyte_utf8_characters' panicked at 'Command was expected to succeed.
stdout = 
 stderr = thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Os { code: 9, kind: Uncategorized, message: "Bad file descriptor" }', src/uu/tail/src/tail.rs:1653:60
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
', tests/common/util.rs:176:9

[Joining7943]

I'm pretty sure this error isn't caused by #3874 but I've added a lot of tests for piped input. I've found a reference in the code of tail to the bad file descriptor problem and the checks for bad file descriptors are disabled. I'll try something to deal with the problem.

[Joining7943]

I think #3910 together with #3919 should at least reduce these kinds of errors. I've also added some debug output in case we're running into these random errors again.

[jhscheer]

I'm pretty sure this error isn't caused by #3874

I agree.

I've found a reference in the code of tail to the bad file descriptor problem and the checks for bad file descriptors are disabled.

These checks were ment to detect a broken FD at program start.
They are disabled because currently they're not possible with rust's stdlib, see the linked issue in the comments.

I'll try something to deal with the problem.

We could implement better error handling for the code: 9, kind: Uncategorized, message: "Bad file descriptor" error.
However I cannot reproduce the test_stdin_default issue on a x86_64 MacBook. My guess is, that it's a problem with the macOS CI. I would simply deactivate this test for macOS if it's run inside the CI.

[sylvestre]

I would simply deactivate this test for macOS if it's run inside the CI.

OK, works for me :) S

[sylvestre]

maybe fixed ;)