Perhaps one of these commits is the reason for this test failure:

ZTST_verbose=2 TESTNUM=Z03 make check
cd Test ; make check
make[1]: Entering directory '/SSD-2/opt/build/zsh-2021-09-07/Test'
if test -n "gcc"; then \
  cd .. && DESTDIR= \
  make MODDIR=`pwd`/Test/Modules install.modules > /dev/null; \
fi
if test -z "$ZTST_handler"; then \
  ZTST_handler=runtests.zsh; \
fi; \
if ZTST_testlist="`for f in ../../../src/zsh-2021-09-07/Test/Z03*.ztst; \
           do echo $f; done`" \
 ZTST_srcdir="../../../src/zsh-2021-09-07/Test" \
 ZTST_exe=../Src/zsh \
 ../Src/zsh +Z -f ../../../src/zsh-2021-09-07/Test/$ZTST_handler; then \
 stat=0; \
else \
 stat=1; \
fi; \
sleep 1; \
rm -rf Modules .zcompdump; \
exit $stat
../../../src/zsh-2021-09-07/Test/Z03run-help.ztst: starting.
ZTST_getsect: read section name: prep
ZTST_getchunk: read code chunk:
  PAGER=cat
  unalias run-help
  autoload +X -Uz $PWD/../Functions/Misc/run-help*
  builtin() {
    case "$1 $2" in
      ( 'getln cmd_args' )
        cmd_args="$BUFFER_STACK"
      ;;
      ( 'print -z' )
      ;;
      ( 'whence -va' )
        print -l "$3 is WHENCE:{$3}"
      ;;
      ( * )
        eval $@
      ;;
    esac
  }
  man() {
    [[ $1 == -w && -n $NO_SUBCMD_MANUALS ]] &&
        return 1
    print "MAN:{${(qq)@}}"
  }
  git svn () {
    print "${(U)0}:{${(qq)@}}"
  }
(eval):3: no matches found:
/opt/build/zsh-2021-09-07/Test/../Functions/Misc/run-help*
ZTST_execchunk: status 1
Test ../../../src/zsh-2021-09-07/Test/Z03run-help.ztst failed: non-zero
status from preparation code:
  PAGER=cat
  unalias run-help
  autoload +X -Uz $PWD/../Functions/Misc/run-help*
  builtin() {
    case "$1 $2" in
      ( 'getln cmd_args' )
        cmd_args="$BUFFER_STACK"
      ;;
      ( 'print -z' )
      ;;
      ( 'whence -va' )
        print -l "$3 is WHENCE:{$3}"
      ;;
      ( * )
        eval $@
      ;;
    esac
  }
  man() {
    [[ $1 == -w && -n $NO_SUBCMD_MANUALS ]] &&
        return 1
    print "MAN:{${(qq)@}}"
  }
  git svn () {
    print "${(U)0}:{${(qq)@}}"
  }
../../../src/zsh-2021-09-07/Test/Z03run-help.ztst: test failed.
ZTST_getchunk: read code chunk:

ZTST_getsect: read section name: test
ZTST_test: looking for new test
ZTST_test: examining line:

ZTST_test: examining line:
  BUFFER_STACK='btrfs --help'
ZTST_getchunk: read code chunk:
  BUFFER_STACK='btrfs --help'
  run-help btrfs
ZTST_test: examining line:
>btrfs is WHENCE:{btrfs}
ZTST_getredir: read redir for '>':
btrfs is WHENCE:{btrfs}
MAN:{'btrfs'}
ZTST_test: examining line:

Running test: btrfs with option flag, no subcmd
ZTST_test: expecting status: 0
Input: /tmp/zsh.ztst.111953/ztst.in, output: /tmp/zsh.ztst.111953/ztst.out,
error: /tmp/zsh.ztst.111953/ztst.terr
ZTST_execchunk: status 127
Test ../../../src/zsh-2021-09-07/Test/Z03run-help.ztst failed: bad status
127, expected 0 from:
  BUFFER_STACK='btrfs --help'
  run-help btrfs
Error output:
(eval):2: command not found: run-help
Was testing: btrfs with option flag, no subcmd
../../../src/zsh-2021-09-07/Test/Z03run-help.ztst: test failed.
ZTST_getsect: read section name: clean
ZTST_getchunk: read code chunk:

**************************************
0 successful test scripts, 1 failure, 0 skipped
**************************************
make[1]: *** [Makefile:190: check] Error 1
make[1]: Leaving directory '/SSD-2/opt/build/zsh-2021-09-07/Test'
make: *** [Makefile:263: check] Error 2


This is the most recent Arch linux, in case that helps.

  - Vin