./dist/setup/setup without execute bit causes cabal to exit silently with code 127

[rrnewton]

I ran into this one thanks to Dropbox.

All my cabal commands started to fail in the same way all of a sudden (no output, error code 127). A cabal clean -v3 revealed the problem and a chmod +x fixed it.

$ cabal clean -v3; echo $?

Using external setup method with build-type Custom Creating ./dist/setup (and its parents) Using Cabal library version 1.8.0.6 Using ./Setup.hs as setup script. ./dist/setup/setup clean --verbose=3 127

[kosmikus]

This is actually more or less a duplicate of #665.