You must install cygwin with those packages :
- zlib-devel (which is in the "Libs" section, but not in "devel" section)
Then download squashfs-tools from sourceforge.
Here is the simple procedure :
tar xvzf squashfs4.3.tar.gz cd squashfs4.3/squashfs-tools make EXTRA_CFLAGS="-Dlinux -DFNM_EXTMATCH='(1<<5)' -D'sigtimedwait(a,b,c)=sigwaitinfo(a,b)'"...et voilà !
I did not found any problem, but this trick replaces "sigtimedwait" with "sigwaitinfo". Those two functions does the same except that sigtimedwait has a timeout. So you may expect some lock up, in some conditions.
Happy squashing with that !