GNU coreutils 9.12: remaining test failures - Sept 2026

This catalogues the remaining GNU coreutils 9.12 test-suite failures so
they can be tracked and worked on individually. It replaces #13841, with the
entries fixed in the meantime removed and the new 9.12 tests added.

Run on main (0.13.0, 3ef4277d5), GNU coreutils 9.12, full make check then
every failure re-run serially to weed out load-induced flakes:
719 tests, 571 PASS, 63 FAIL, 5 ERROR, 78 SKIP.

Several tests are new in 9.12 (marked (new)) and several older ones were
tightened upstream, so this list is noticeably longer than the 9.11 one.

Status: entries carrying a PR number have a fix under review; each was
verified with a Rust test plus a re-run of the GNU test. Together they turn 12
of the failures below into passes.

---

Crashes (panics) - highest priority

• printf/printf.sh and seq/seq-precision.sh: panic Formatting argument out of range in src/uucore/src/lib/features/format/num_format.rs:434 on a large format precision - a %f precision above u16::MAX is now written and zero-padded without format! - PR #14714 (see also PR #14713)
• misc/write-errors.sh: numfmt panics on ENOSPC - .unwrap() on a write error in src/uu/numfmt/src/format.rs:976 - numfmt now reports write error: ... and treats it as fatal whatever --invalid says (the test itself still fails on the other utilities) - PR #14715
• shuf/shuf.sh: panic could not initialize ThreadRng: Function not implemented when getrandom is made to fail

---

FAILED Tests

• cat/cat-distinct-err.sh (new): read and write errors must be distinguished (cat: write error: ... vs cat: -: ...) - PR #14721
• comm/dash-dash.sh (new): comm - - reading stdin twice - it currently hangs (the test times out), it is not just a wrong result
• csplit/csplit.sh: csplit '//' is rejected instead of being treated as an empty pattern - empty // and %% accepted, plus the split in progress is reported before a read error - PR #14716
• cut/bounded-memory.sh: cut must use bounded memory (intermittent)
• date/date.pl: comprehensive date parsing
• date/date-debug.sh: date --debug output
• date/date-locale-hour.sh: 12- vs 24-hour clock per locale (intermittent)
• date/date-tz.sh: a time that does not exist in the TZ (DST spring-forward) must be rejected
• dd/misc.sh: dd and --, plus the strace-injected error paths
• dd/nocache.sh: dd ... nocache on a pipe wrongly reports failed to discard cache: Illegal seek
• df/df-output.sh: df -m --output=size - -m is rejected when combined with --output
• du/block-size.sh (new): du --block-size / BLOCK_SIZE must print the unit suffix (98KiB, not 98)
• du/max-depth.sh: du --max-depth=-1 must give du: invalid maximum depth '-1', not a clap error - PR #14709
• env/env-signal-handler.sh: env --default-signal=PIPE
• fold/fold.pl: fold -w0 error text (Numerical result out of range vs Result too large), the overflow case used the wrong errno text too - PR #14706
• head/quote-headers.sh (new): head must quote file names in ==> ... <== headers - PR #14710
• join/join.pl: error text and exit status on invalid usage
• ls/color-symlink-target.sh (new): unparsable LS_COLORS diagnostic must not be prefixed with warning: - PR #14708
• ls/ls-time.sh: ls -l time style must follow the locale (Jan 15 1998 vs ISO)
• ls/m-option.sh: ls -m line wrapping
• misc/close-stdin.sh (new): programs run with stdin initially closed must diagnose EBADF
• misc/getopt_vs_usage.sh: the test reads the option tables out of GNU's own src/*.c and greps our --help for each. Besides uname -p/-i and wc --debug (genuine gaps, fix ready), it reports options we do not implement at all: cp --keep-directory-symlink, env --env0-from, install --debug, ln -F/--directory, mv --no-copy, pr -c/-v/--output-tabs/--show-control-chars/--show-nonprinting, ptx --format, split -u/--unbuffered, stat --cached. Of little value for us, so it is being skipped through util/gnu-patches/ - PR #14717
• misc/io-errors.sh: programs diagnose write errors (intermittent)
• misc/just-created.sh (new): cp/mv/install must not overwrite a just-created file - PR #14724 (install)
• misc/printenv.sh: printenv must honour QUOTING_STYLE
• misc/read-errors.sh: programs diagnose read errors
• misc/responsive.sh: programs stay responsive to input
• misc/stdbuf.sh: stdbuf line/block buffering (intermittent)
• misc/traversal-missing.sh (new): traversal races must be ignored (chmod reports Permission denied where GNU reports the race)
• misc/usage_vs_refs.sh - PR #10896: every supported option has references in docs
• misc/warning-errors.sh: failure to write warnings is handled gracefully
• misc/write-errors.sh: programs promptly diagnose write errors - numfmt's panic is fixed by PR #14715, but ~40 utilities still fail to diagnose EBADF/ENOSPC, and cut -b1- /dev/zero aborts on a 16MiB allocation
• od/od.pl: od quotes bad -j/-N arguments as $'a\t' instead of 'a\t'
• pr/bounded-memory.sh: pr on files larger than memory (intermittent)
• pr/options.sh (new): pr numeric option diagnostics (invalid page range '0', '-l PAGE_LENGTH' invalid number of lines, ...)
• printf/printf.sh: large format precision (panic, see above) - PR #14714
• pr/pr-tests.pl: comprehensive pr page-formatting tests
• ptx/ptx.pl: invalid -S regex must not print a multi-line regex crate error
• ptx/word-regex-loop.sh (new): a nullable --word-regexp must not produce extra output - PR #14722
• seq/seq-precision.sh: large format precision (panic, see above) - PR #14714
• shred/fifo.sh (new): shred on a FIFO - invalid file type / failed to open for writing diagnostics
• shred/shred-remove.sh: shred --remove renaming in an unwritable directory
• shuf/shuf.sh: RNG failure handling (panic, see above) and --input-range with operands
• sort/sort.pl: sort --parallel invalid argument diagnostics
• sort/sort-buffer-size.sh (new): buffer sizing for streaming input
• sort/sort-compress-proc.sh: compression subprocesses
• sort/sort-stale-thread-mem.sh: stale thread memory (intermittent)
• split/split-io-err.sh: I/O errors via /dev/full
• stat/stat-fmt.sh: stat --format with %q-style quoting escapes
• stat/stat-nanoseconds.sh: %:X, %:Y, ... nanosecond format strings
• tail/debug.sh: tail --debug output
• tail/follow-name.sh: --follow=name must not imply --retry (intermittent)
• tail/follow-symlink.sh (new): tail -f on a symlink must keep following the target
• tail/inotify-dir-recreate.sh: switch to polling when the directory is recreated (intermittent)
• tail/inotify-rotate-resources.sh: tail -F must not leak inotify resources
• tail/pid-pipe.sh: tail --pid=PID fifo exits responsively (intermittent)
• tail/pipe-f.sh: tail -f must not hang on a pipe (intermittent) - it expects ==> 'standard input' <==, so the header-quoting fix makes it pass - PR #14710
• tail/quote-headers.sh (new): tail must quote file names in headers - head and tail now shell-escape the name (including 'standard input') - PR #14710
• tail/symlink.sh: symlink tracking (intermittent)
• tee/short-write.sh (new): tee must handle a short write (writes the whole buffer again)
• test/test.pl: test N -eq M exit statuses for some operands
• unexpand/unexpand.pl: tab stop is too large vs tab stop value is too large - PR #14707
• wc/wc.pl: wc -c -m on multibyte input reports the wrong count

---

ERROR Tests

• env/env.sh, env/env0-from.sh: env --debug must quote the executed command (executing: './truetrue') - NOTE: Upstream is working on changing this
• env/printenv.sh: (see INCOMPATIBLE - LD_PRELOAD)
• rm/ext3-perf.sh, rm/many-dir-entries-vs-OOM.sh: set-up fails with Command could not be run: Argument list too long (os error 7) - we should fall back like GNU instead of erroring out

---

SKIPPED Tests

• dd/nocache_fail.sh: diagnose failure to drop caches
• id/gnu-zero-uids.sh: id must fail for processes with zero UIDs
• install/stdin.sh (new): install reading from /dev/stdin
• misc/tty-quoting.sh (new): quoting when stdout is a terminal
• mkdir/smack-no-root.sh: SMACK labels for mkdir/mknod/mkfifo
• mv/i-3.sh: mv file unwritable-file prompts, mv -f does not
• sort/sort-locale.sh: locale-aware sort ordering
• stty/bad-speed.sh, stty/stty.sh, stty/stty-invalid.sh, stty/stty-pairs.sh, stty/stty-row-col.sh: stty settings

The stty/* and a few other entries are skipped because the runner has no
controlling tty (or no SELinux/SMACK/ACL/xattr support), rather than being real
gaps.

---

INCOMPATIBLE Tests

Tests using LD_PRELOAD or gdb breakpoints cannot be fixed without matching
internal implementation details:

• cp/nfs-removal-race.sh (LD_PRELOAD): NFS client removal race during cp S D
• df/skip-duplicates.sh (LD_PRELOAD): duplicate mount-list entry injection
• env/printenv.sh, misc/printenv.sh (LD_PRELOAD): printenv with a corrupted environ
• nproc/nproc-quota.sh (LD_PRELOAD): cgroup-quota injection for nproc
• rm/r-root.sh (LD_PRELOAD + gdb): tries to remove / recursively
• rm/rm-readdir-fail.sh (LD_PRELOAD) - PR #9604: simulates readdir failures
• tail/inotify-race.sh, tail/inotify-race2.sh (gdb): races during the initial read

Several other failures above (cat/cat-distinct-err, dd/fail-ftruncate-fstat,
dd/misc, misc/read-errors, misc/traversal-missing, shred/fifo,
shuf/shuf, tail/debug, tee/short-write) use strace fault injection;
they are not structurally impossible - they fail because our syscall sequence or
our error messages differ.

• dd/fail-ftruncate-fstat.sh (strace): dd must stop copying when ftruncate/fstat fail

Start by running the mentioned full make check, then choose one independently actionable test such as cat/cat-distinct-err.sh or du/block-size.sh and read its corresponding implementation and test. Done means the selected test passes with the expected GNU-compatible behavior; entries marked incompatible or dependent on upstream work are not suitable starting points.