sdist race condition and temp dir customization #1222
Description
Currently if two sdist commands are ran at the same time there is a race condition. One sdist command can be purging the temp files under {packagename}-{packageversion} in the setup.py directory while the other is zipping it, causing error messages like this
Creating tar archive
removing 'cosmo4d-0.0.0' (and everything under it)
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/setup.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/tests/test_engine.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/tests/test_pmesh.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/tests/test_map2d.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/tests'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/iotools.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/pmeshengine.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/__init__.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/version.py'
error removing cosmo4d-0.0.0: [Errno 2] No such file or directory: 'cosmo4d-0.0.0/cosmo4d/options.py'
Processing /tmp/VlnJRkP/cosmo4d-0.0.0.tar.gz
Skipping bdist_wheel for cosmo4d, due to binaries being disabled for it.
One possible solution to avoid the racing is to allow an argument --temproot to allow redirection of the temp directory to a different location. Then the caller to setup.py (or sdist itself) can use mktemp -d to avoid building sdist from the same temp dir; or at least to minimize the chances of racing.