scanning the -s style file is not reported and errors/warnings are not shown

[FrankMittelbach]

When you use upmendex then the scanning of the style file doesn't report any ignored lines (like makeindex does) so you don't have an way to easily find a mistake, e.g. I mispelled "icu_attributes" as "icu_attribute" and wondered why stuff didn't got sorted the way I expected it to be.

would be good if instead of

This is upmendex version 0.54 (TeX Live 2021).
Scanning dictionary file ./xx.dic....done.
Scanning input file xx.idx....done (33 entries accepted, 0 rejected).
33 entries accepted, 0 rejected.
Sorting index....done(139 comparisons).
Sorting pages....done(8 comparisons).
Making index file....done.
0 warnings, written in xx.ilg.

you get also

Scanning style file ./xx.ist..done (2 attributes redefined, 4 ignored).

and in the ilg file

Scanning style file ./xx.ist..
** Input style error (file = ./xx.ist, line = 4):
   -- Unknown specifier heading_flag.
** Input style error (file = ./xx.ist, line = 6):
   -- Unknown specifier letter_head.
** Input style error (file = ./xx.ist, line = 8):
   -- Unknown specifier character_order.
** Input style error (file = ./xx.ist, line = 23):
   -- Unknown specifier icu_attributes.
done (2 attributes redefined, 4 ignored).

[t-tk]

Thank you for your suggestion.

I committed TeX Live svn r60342. Now upmendex outputs warnings on console stderr and *.ilg file as follows:

This is upmendex version 0.58 [ICU 68.2] (TeX Live 2022/dev).
Scanning style file ./styA05.ist.
Warning: Unknown specifier (unknown_first).
Warning: Unknown specifier (unknown_second)....done.
Scanning input file alpha_en.idx....done (60 entries accepted, 0 rejected).
60 entries accepted, 0 rejected.