test_create_one_fifo_already_exists intermittent failure

    bin: "/home/runner/work/coreutils/coreutils/target/debug/coreutils"
    run: /home/runner/work/coreutils/coreutils/target/debug/coreutils mkfifo abcdef abcdef
    test test_mkfifo::test_create_one_fifo_already_exists ... FAILED

    failures:

    ---- test_mkfifo::test_create_one_fifo_already_exists stdout ----
    ---- test_mkfifo::test_create_one_fifo_already_exists stderr ----


    failures:
        test_mkfifo::test_create_one_fifo_already_exists

    test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 5135 filtered out; finished in 0.19s
    
  stderr ───

    thread 'main' (37702) panicked at tests/by-util/test_mkfifo.rs:83:10:
    assertion failed: `(left == right)`

    Diff < left / right > :
     mkfifo: cannot create fifo 'abcdef': File exists
    <LLVM Profile Error: Failed to write file "/home/runner/work/coreutils/coreutils/coverage/traces/coverage-9324049985853773752_2.profraw": Permission denied
     


    note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Start with tests/by-util/test_mkfifo.rs, especially test_mkfifo::test_create_one_fifo_already_exists and the assertion at line 83. Reproduce the reported command and inspect the expected stderr alongside the LLVM Profile Error; done means the intermittent test failure is understood and the test passes reliably.