@tgamblin @alalazo

The ibmisc package depends on py-cython: https://github.com/LLNL/spack/blob/develop/var/spack/repos/builtin/packages/ibmisc/package.py

When I run spack setup from a "clean" environment, spec['py-cython'].prefix.bin is not ending up in the $PATH. But if I spack load py-cython before running spack setup, it DOES work out OK (hence why I didn't catch this problem earlier). I'm 90% confident that the same behavior would be observed running spack install as with spack setup.

Looking at the generated module file for py-cython, I see that it adds to $PATH correctly.

Does anyone know why this is happening?

(Remember that the $PATH from spconfig.py is taken directly from the environment that Spack WOULD HAVE used in a regular spack install; see install_setup() in lib/spack/spack/package.py.)