>I can't build v3.31 (and 3.32beta) on a Solaris 8 host. 
>minizip/mztools.c:19: stray '\' in program

Files in src/minizip/ are in DOS format (CRLF) and the 
compiler doesn't like it (Unix format - LF)

Just strip CR from the *.c and *.h files (man dos2unix) and 
it will compile file

I'll fix this issue in the next release.