cygwin/gcc build conflicts

Has anyone attempted to install multiple versions of cygwin and gcc? I now have three SDK’s that use them, and each vendor will only support one specific version. Of course no two are on the same build, so I can’t simply install one copy and use it for all three. Each vendor also adds their own proprietary extension libraries. I can’t continue to use three different computers for tham.

I have the same problem…

How did you resolved it?

This is the script I use to switch to cygwin420 from cygwin340
c:\cygwin340\bin\umount /
c:\cygwin340\bin\umount /usr/bin
c:\cygwin340\bin\umount /usr/lib
c:\cygwin340\bin\mount c:\cygwin420 /
c:\cygwin340\bin\mount c:\cygwin420\bin /usr/bin
c:\cygwin340\bin\mount c:\cygwin420\lib /usr/lib
c:\cygwin340\bin\mount

This is a script I use to switch back:
c:\cygwin420\bin\umount /
c:\cygwin420\bin\umount /usr/bin
c:\cygwin420\bin\umount /usr/lib
c:\cygwin420\bin\mount c:\cygwin340 /
c:\cygwin420\bin\mount c:\cygwin340/bin /usr/bin
c:\cygwin420\bin\mount c:\cygwin340/lib /usr/lib
c:\cygwin340\bin\mount

modify and use on your own risk

Is this a dos .bat script? Not a cygwin .sh script?