[Cython] Failing test reimport_from_subinterpreter

[Jeroen Demeyer]

On 2018-10-21 15:44, Stefan Behnel wrote:
> Maybe print "sys.path" and "sys.meta_path" in a couple of places?

So I did and the problem is indeed related to sys.path.

When running *only* the reimport_from_subinterpreter tests, sys.path 
starts with the following entries:

''
'/home/jdemeyer/sage-test/local/var/tmp/sage/build/cython-0.29/src/TEST_TMP/support/lib.linux-ppc64le-2.7'
'/home/jdemeyer/sage-test/local/var/tmp/sage/build/cython-0.29/src'
'/home/jdemeyer/sage-test/local/var/tmp/sage/build/cython-0.29/src/TEST_TMP/run/reimport_from_subinterpreter' 
  # <----
'/home/jdemeyer/sage-test/local/lib/python27.zip'
'/home/jdemeyer/sage-test/local/lib/python2.7'

When running all tests, sys.path starts with the following entries:

''
'/home/jdemeyer/sage-test/local/var/tmp/sage/build/cython-0.29/src/TEST_TMP/support/lib.linux-ppc64le-2.7'
'/home/jdemeyer/sage-test/local/var/tmp/sage/build/cython-0.29/src' 
'/home/jdemeyer/sage-test/local'  # <----
'/home/jdemeyer/sage-test/local/lib/python27.zip'
'/home/jdemeyer/sage-test/local/lib/python2.7'

The entries marked with # <---- are different but I don't know why. 
Further suggestions for debugging are more than welcome...

In both cases, the initial entry ('') is dropped in the sub-interpreter. 
I assume that this is a feature.