PMIx: add PMIx package to Spack (#5426)

Open MPI has been relying on versions of PMIx since the 2.0.0
release.  Although the embedded version can be used, it makes
more sense long term for Spack to know about the PMIx package,
and to build Open MPI against PMIx as an external package.

There are other software components that may eventually be
reliant on PMIx including MPICH, GASNet, the OpenSHMEM reference
implementation, etc.

This is also partly motivated by the desire to have ECP ST
projects to be released through Spack.

Signed-off-by: Howard Pritchard <howardp@lanl.gov>

var/spack/repos/builtin/packages/pmix/package.py

@@ -0,0 +1,71 @@
+##############################################################################
+# Copyright (c) 2013-2017, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the NOTICE and LICENSE files for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
+
+from spack import *
+
+
+class Pmix(AutotoolsPackage):
+    """The Process Management Interface (PMI) has been used for quite some time
+       as a means of exchanging wireup information needed for interprocess
+       communication. Two versions (PMI-1 and PMI-2) have been released as part
+       of the MPICH effort. While PMI-2 demonstrates better scaling properties
+       than its PMI-1 predecessor, attaining rapid launch and wireup of the
+       roughly 1M processes executing across 100k nodes expected for exascale
+       operations remains challenging.  PMI Exascale (PMIx) represents an
+        attempt to resolve these questions by providing an extended version
+       of the PMI definitions specifically designed to support clusters up
+       to and including exascale sizes.  The overall objective of the project
+       is not to branch the existing definitions - in fact, PMIx fully
+       supports both of the existing PMI-1 and PMI-2 APIs - but rather to
+       (a) augment and extend those APIs to eliminate some current restrictions
+       that impact scalability, (b) establish a standards-like body for
+       maintaining the definitions, and (c) provide a reference implementation
+       of the PMIx standard that demonstrates the desired level of
+       scalability."""
+
+    homepage = "https://pmix.github.io/pmix"
+    url      = "https://github.com/pmix/pmix/releases/download/v2.0.1/pmix-2.0.1.tar.bz2"
+
+    version('2.0.1',    'ba3193b485843516e6b4e8641e443b1e')
+    version('2.0.0',    '3e047c2ea0ba8ee9925ed92b205fd92e')
+    version('1.2.3',    '102b1cc650018b62348b45d572b158e9')
+    version('1.2.2',    'd85c8fd437bd88f984549425ad369e9f')
+    version('1.2.1',    'f090f524681c52001ea2db3b0285596f')
+    version('1.2.0',    '6a42472d5a32e1c31ce5da19d50fc21a')
+
+    depends_on('libevent')
+
+    def configure_args(self):
+        spec = self.spec
+        config_args = [
+            '--enable-shared',
+            '--enable-static'
+        ]
+
+        # external libevent support (needed to keep Open MPI happy)
+        config_args.append(
+            '--with-libevent={0}'.format(spec['libevent'].prefix))
+
+        return config_args