sysconfig.get_config_var('srcdir') seems to return the current working directory rather than a directory related to the source directory. For example (starting from the repository root)-- $ mkdir foo $ cd foo $ ../python.exe Python 3.3.0b1 (default:5d43154d68a8, Jul 8 2012, 18:23:20) [GCC 4.2.1 Compatible Apple Clang 3.1 (tags/Apple/clang-318.0.58)] on darwin >>> import sysconfig >>> sysconfig.get_config_vars('srcdir') ['/.../cpython/foo'] >>> import sys >>> sys.executable '/.../cpython/foo/../python.exe' This may be the cause or related to issue 15300: "test directory doubly-nested running tests with -j/--multiprocess".
I searched a little before. There is issue 12141, "sysconfig.get_config_vars('srcdir') fails in specific cases," but that issue is closed. In the comments there, Antoine seems to be describing the bug I describe here, but I'm not sure an issue was filed: http://bugs.python.org/issue12141#msg136493