test_create_one_fifo_with_non_file_permission_mode intermittent failure

    running 1 test
    bin: "/home/runner/work/coreutils/coreutils/target/debug/coreutils"
    run: /home/runner/work/coreutils/coreutils/target/debug/coreutils mkfifo abcd -m 1777
    test test_mkfifo::test_create_one_fifo_with_non_file_permission_mode ... FAILED

    failures:

    ---- test_mkfifo::test_create_one_fifo_with_non_file_permission_mode stdout ----
    ---- test_mkfifo::test_create_one_fifo_with_non_file_permission_mode stderr ----


    failures:
        test_mkfifo::test_create_one_fifo_with_non_file_permission_mode

    test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 5169 filtered out; finished in 0.16s
    
  stderr ───

    thread 'main' (42243) panicked at tests/by-util/test_mkfifo.rs:53:10:
    assertion failed: `(left == right)`

    Diff < left / right > :
     mkfifo: mode must specify only file permission bits
    <LLVM Profile Error: Failed to write file "/home/runner/work/coreutils/coreutils/coverage/traces/coverage-6931721886030836390_0.profraw": Permission denied

https://github.com/uutils/coreutils/actions/runs/24285074447/job/70912994688?pr=11759

Start with tests/by-util/test_mkfifo.rs at the failing assertion and reproduce the mkfifo command from the linked GitHub Actions job. Investigate the intermittent LLVM profile permission error and make the test run reliably, then verify the targeted test passes in the affected CI configuration.