"cmake -E tar" ignores COPYFILE_DISABLE environment variable
I use cpack to generate source tar balls. If I do this on OS X, this results in lots of ._*
files (corresponding to extended attribute data) being included. If you use "file(GLOB *.cpp)" in your CMakeLists.txt (as I do), then you get lots of files that don't compile on any OS other than OS X. I believe that cpack uses "cmake -E tar" to create the TGZ files, so the problem is probably in this code. On OS X you can set the environment variable COPYFILE_DISABLE to prevent extended attribute data from being included in tar balls. This setting is used by tar, bsdtar, and gnutar on OS X, but "cmake -E tar" ignores it. Alternatively, a CPack/CMake variable to control whether extended attribute data should be included would also be good.