こちらは Ubuntu 24.04 でのテストです.
Ubuntu で配布されているパッケージのバイナリを使用しています.
mendex では Segmentation fault,upmendex では問題なしでした.
$ grep PRETTY_NAME /etc/os-release
PRETTY_NAME="Ubuntu 24.04.2 LTS
$ uname -svrmopi; bash --version | head -1; printf '%s\n' '\indexentry{entryA}{0}' '\indexentry{entryA}{-1.1.1}' | mendex -s <( printf '%s\n' 'page_compositor "."' ); printf '%s\n' "${PIPESTATUS[@]}"
Linux 6.8.0-63-generic #66-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 13 20:25:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu)
This is mendex version 3.6 [12-Jun-2022] (utf8.uptex) (TeX Live 2023).
Scanning style file /dev/fd/63....done.
Scanning input file stdin....done (2 entries accepted, 0 rejected).
2 entries accepted, 0 rejected.
Sorting index....done(0 comparisons).
Sorting pages....done(2 comparisons).
Making index file.\begin{theindex}
Segmentation fault (core dumped)
0
139
$ uname -svrmopi; bash --version | head -1; printf '%s\n' '\indexentry{entryA}{0}' '\indexentry{entryA}{-1.1.1}' | upmendex -s <( printf '%s\n' 'page_compositor "."' ); printf '%s\n' "${PIPESTATUS[@]}"
Linux 6.8.0-63-generic #66-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 13 20:25:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu)
This is upmendex version 1.07 [ICU 74.2] (TeX Live 2023).
Scanning style file /dev/fd/63....done.
Scanning input file stdin....done (2 entries accepted, 0 rejected).
2 entries accepted, 0 rejected.
Sorting index....done(0 comparisons).
Sorting pages....done(2 comparisons).
Making index file.\begin{theindex}
\item entryA, -1.1.1, 0
\end{theindex}
...done.
0 warnings, written in stderr.
Output written in stdout.
0
0
$
makeindex については,同様に Segmentation fault やソート順がおかしかったりします.
$ uname -svrmopi; bash --version | head -1; printf '%s\n' '\indexentry{entryA}{0}' '\indexentry{entryA}{1234567890123456789}' '\indexentry{entryA}{12345678901234567890}' | makeindex
Linux 6.8.0-63-generic #66-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 13 20:25:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu)
This is makeindex, version 2.17 [TeX Live 2023] (kpathsea + Thai support).
Scanning input file stdin....done (3 entries accepted, 0 rejected).
Sorting entries....Segmentation fault (core dumped)
$ uname -svrmopi; bash --version | head -1; printf '%s\n' '\indexentry{entryA}{0}' '\indexentry{entryA}{12345678901234567890}' | makeindex
Linux 6.8.0-63-generic #66-Ubuntu SMP PREEMPT_DYNAMIC Fri Jun 13 20:25:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu)
This is makeindex, version 2.17 [TeX Live 2023] (kpathsea + Thai support).
Scanning input file stdin....done (2 entries accepted, 0 rejected).
Sorting entries....done (2 comparisons).
Generating output file stdout...\begin{theindex}
.
\item entryA, 12345678901234567890, 0
\end{theindex}
done (5 lines written, 0 warnings).
Output written in stdout.
Transcript written in stderr.
$