Having LFN=n in DJGPP.ENV is not enough.
c:\windows> grep hard_to_find *
produces something like:
grep: Black Thatch.bmp: No such file or directory (ENOENT)
...

Obviously, * is expanded into long file names.

Set LFN=n in environment (say, in AUTOEXEC.BAT).

This way, startup (crt1) will see LFN=n before
it starts to expand wildcards.

Rewrite __crt1_startup ().

Old code:
1. Make our environment from dos environment.
2. Update LFN.
3. Read arguments.
   Possibly, assuming LFN=y for response files, etc.
4. Read environment file (DJGPP.ENV).
   Possibly, using __crt0_argv[0], obtained in 3rd step.
5. Update LFN.
6. ..., call `main'.

New code:
1. Make our environment from dos environment.
2. Find program name (from stub or PSP).
3. Read environment file (using program name from 2nd step).
4. Update LFN.
5. Read the rest of arguments.
6. ..., call `main'.