This is makeindex, version 2.15 [TeX Live 2020] (kpathsea + Thai support).
Scanning input file output/test.idx....done (12 entries accepted, 0 rejected).
Sorting entries....done (50 comparisons).
Generating output file output/test.ind....done (40 lines written, 0 warnings).
Output written in output/test.ind.
Transcript written in output/test.ilg.