Q: I get error messages saying "Unknown filetype" from GCC.
Q: Since a few days ago, whenever I try to run most of the DJGPP
programs, they print a message "C:\DJGPP\BIN\prog.exe: not
COFF" and just terminate. Help!!!
A: It might be that your DJGPP programs and/or STUBIFY.EXE
are infected by a virus. (This is not a joke! It did happen to
a few of us and can happen even to you.) As the DOS stub prepended to
the DJGPP programs is very short, many viruses cannot attach themselves
to it without overwriting the beginning of the DJGPP COFF image which
specifies vital information such as location and length of various
program sections, therefore triggering this error from the code in the
stub that loads the COFF image.
Another possible cause of the "Unknown filetype" message is that you
mix a v2.0 gcc.exe driver with cc1plus.exe, cc1.exe
or other programs from an old v1.x distribution.