From a714377123cf2aefb895badfbf9d4baf81b39654 Mon Sep 17 00:00:00 2001 From: Barry Smith Date: Sun, 30 Oct 2016 19:13:16 -0500 Subject: python: PYTHONHOME may not be the same as the prefix of the python executable (#2173) On MacOS, brew installs /usr/local/bin/python but the Python prefix is not /usr/local/bin Use the python command sys.exec to get the correct directory, instead of the ad hoc self.prefix previously used This was a bear to debug; been driving me nuts since I started using spack. Since spack passes PYTHONHOME down to package builds in the environment it was passing PYTHONHOME of /usr/local/bin to the PETSc build that uses Python so the PETSc Python ./configure errored immediately with ImportError: No module named site since python could find no python modules. Todd Gamblin pointed out that my first try to fix this was wrong since it assumed the spack python was the same python used to run spack. Elizabeth Fischer suggested how to get it to work also with python3 Funded-by: IDEAS Project: IDEAS/xSDK Time: 7 hours Thanks-to: Todd Gamblin, Elizabeth Fischer --- var/spack/repos/builtin/packages/python/package.py | 23 ++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'var') diff --git a/var/spack/repos/builtin/packages/python/package.py b/var/spack/repos/builtin/packages/python/package.py index f3380cf75d..7fe2cab897 100644 --- a/var/spack/repos/builtin/packages/python/package.py +++ b/var/spack/repos/builtin/packages/python/package.py @@ -202,8 +202,27 @@ class Python(Package): def setup_dependent_environment(self, spack_env, run_env, extension_spec): """Set PYTHONPATH to include site-packages dir for the extension and any other python extensions it depends on.""" - pythonhome = self.prefix - spack_env.set('PYTHONHOME', pythonhome) + # The python executable for version 3 may be python3 or python + # See https://github.com/LLNL/spack/pull/2173#issuecomment-257170199 + pythonex = 'python{0}'.format('3' if self.spec.satisfies('@3') else '') + if os.path.isdir(self.prefix.bin): + base = self.prefix.bin + else: + base = self.prefix + if not os.path.isfile(os.path.join(base, pythonex)): + if self.spec.satisfies('@3'): + python = Executable(os.path.join(base, 'python')) + version = python('-c', 'import sys; print(sys.version)', + output=str) + if version.startswith('3'): + pythonex = 'python' + else: + raise RuntimeError('Cannot locate python executable') + else: + raise RuntimeError('Cannot locate python executable') + python = Executable(os.path.join(base, pythonex)) + prefix = python('-c', 'import sys; print(sys.prefix)', output=str) + spack_env.set('PYTHONHOME', prefix.strip('\n')) python_paths = [] for d in extension_spec.traverse(deptype=nolink, deptype_query='run'): -- cgit v1.2.3-60-g2f50