Here are the failing GNU tests as of 2025-11-10
I hope to complete this issue, either by fixing tests, or at least providing a reason explaining what's missing in our implementation.

https://uutils.github.io/coreutils/docs/test_coverage.html

Replace #4627

FAILED

• basenc

  • base64.pl
  • basenc.pl (basenc: Fix basenc.pl GNU-compat tests pass #9203)
  • bounded-memory.sh (introduced with v9.9)

• cat

  • cat-self.sh (fix(cat): refine unsafe overwrite detection for appending files #9122)

• cksum

  • b2sum.sh (hashsum: Fix length processing to fix last GNU test #9569)
  • cksum-base64-untagged.sh (introduced with v9.9) (cksum: Fix GNU test cksum-base64-untagged #9344)
  • cksum-c.sh (cksum: Fix GNU test cksum-c.sh after bump to 9.9 #9511)
  • cksum.sh (Fix hardware capabilities detection; cksum --debug #9603)

• cp

  • cp-a-selinux.sh
  • link_heap.sh
  • preserve-gid.sh

• date

  • date-debug.sh
  • date-ethiopia.sh (reason: Missing translation)
  • date-iran.sh (reason: Missing translation)
  • date-locale-hour.sh (introduced with v9.9)
  • date-thailand.sh (reason: Missing translation)
  • date.pl

• dd

  • no-allocate.sh
  • nocache_eof.sh
  • nocache_fail.sh
  • skip-seek-past-file.sh
  • stderr.sh

• du

  • files0-from.pl (du: handle --files0-from=- with piped in - #8985)

• env

  • env-signal-handler.sh

• fmt

  • non-space.sh

• fold

  • fold-characters.sh (fix(fold): GNU fold-characters.sh test #9126)
  • fold-nbsp.sh (fix(fold): GNU fold-characters.sh test #9126)
  • fold-zero-width.sh
  • fold.pl (Fold: Adding combining character support #9328)

• install

  • basic-1.sh (install: fix the error message #9188)

• ls

  • ls-misc.pl
  • stat-free-symlinks.sh

• misc

  • close-stdout.sh
  • nohup.sh
  • option-aliases.sh (date: add --uct alias and allow multiple option aliases together #9181)
  • stdbuf.sh
  • tee.sh
  • time-style.sh (pr: fix header formatting for custom date formats starting with '+' #9252)
  • tsort.pl
  • unexpand.pl (unexpand: add support for extended tab stop syntax (+N and /N) #9265)
  • write-errors.sh

• numfmt

  • numfmt.pl

• od

  • od-float.sh (fix(od):fix GNU coreutils test od float.sh #9534)
  • od.pl (od: fix GNU od.pl #9334)

• printf

  • printf-surprise.sh (printf: handle extremely large format widths gracefully to fix GNU test panic #9133)

• ptx

  • ptx-overrun.sh
  • ptx.pl

• readlink

  • readlink-posix.sh (fix(readlink): emit GNU-style Invalid argument for non-symlinks #9189)

• rm

  • one-file-system.sh
  • rm1.sh

• seq

  • seq-epipe.sh

• shred

  • shred-passes.sh

• sort

  • sort-compress.sh (sort: make compression program failures non-fatal, warn and fallback to plain files #9266)
  • sort-continue.sh (fix(sort): GNU sort-continue.sh test #9107)
  • sort-debug-keys.sh
  • sort-debug-warn.sh
  • sort-field-limit.sh (Add legacy +POS/-POS handling in sort to pass GNU sort-field-limit test #9501)
  • sort-float.sh
  • sort-h-thousands-sep.sh
  • sort-merge-fdlimit.sh
  • sort-month.sh
  • sort.pl

• tac

  • tac-2-non-seekable.sh

• tail

  • follow-name.sh
  • follow-stdin.sh
  • inotify-rotate-resources.sh
  • overlay-headers.sh
  • pid-pipe.sh
  • pipe-f.sh
  • symlink.sh
  • tail.pl

• tty

  • tty-eof.pl (ptx: implement GNU mode with dumb terminal format #9573)

• wc

  • wc-cpu.sh

SKIPPED

• cp
  • cp-mv-enotsup-xattr.sh
  • nfs-removal-race.sh
• csplit
  • csplit-io-err.sh
• df
  • no-mtab-status.sh
  • skip-duplicates.sh
  • skip-rootfs.sh
• du
  • bigtime.sh (update gnu ref to 9.9 + improve the script #9216)
• id
  • gnu-zero-uids.sh
  • smack.sh
• misc
  • coreutils.sh (reason: meta test ?) (build-gnu.sh: Enable misc/coreutils.sh #9572)
• mkdir
  • smack-no-root.sh
  • smack-root.sh
  • writable-under-readonly.sh
• mv
  • hardlink-case.sh
  • i-3.sh
• nproc
  • nproc-quota.sh
• numfmt
  • mb-non-utf8.sh
• pr
  • pr-tests.pl
• rm
  • fail-eperm.xpl
  • r-root.sh (reason: need root in the testsuite ?)
  • rm-readdir-fail.sh
• stty (reason: testsuite env not adapted ?)
  • bad-speed.sh
  • stty-invalid.sh
  • stty-pairs.sh
  • stty-row-col.sh
  • stty.sh
• tac
  • tac-continue.sh
• tail
  • inotify-dir-recreate.sh
  • inotify-race.sh
  • inotify-race2.sh
• timeout
  • timeout-group.sh