We were getting random fails in Community sources ( 133.193, 137, others ) when we ran ANT on build.xml (build->all) despite the project itself making (build->make) properly. The failure was early, just a minute or so, and consistent with 5 errors being reported but the errors and stack traces themselves were non-informative.
Since we were convinced that not that many builds could fail, we tried moving the release to a folder just under C:\ , which resulted in the errors going away.
Previously we thought this had to do with the length of the paths, but it turns out it's an undocumented bug- there can be no space in the name of the path in which community is installed.
created a directory named: a b ( that is: aSPACEb)
try ANT build.
Community still makes nevertheless.
Haven't seen avoiding this as a requirement in building community using ANT. It seems like it has to do with some part of the build using \ (windows backwards slash) instead of the file protocol / (forwards slash) when forming path names. Purely a guess. What we know is that if Community is installed in a directory with spaces in the absolute path name leading up to it, then ANT will fail when running build.xml