pbs: new virtual package (#24568)

* pbs: new virtual package

Some of our clusters have an older installation of
libtorque and tm.h that are *not* from OpenPBS. Using the current
openpbs dependency for openmpi causes concretization errors due to
restrictions on older python and hwloc requirements that don't apply,
even with an external non-buildable installation.
The new 'torque' bundle package allows users to point to that external
installation without problems.

Detailed description of torque by Sergey Kosukhin <skosukhin@gmail.com>

etc/spack/defaults/packages.yaml

@@ -43,6 +43,7 @@ packages:
       opencl: [pocl]
       onedal: [intel-oneapi-dal]
       osmesa: [mesa+osmesa, mesa18+osmesa]
+      pbs: [openpbs, torque]
       pil: [py-pillow]
       pkgconfig: [pkgconf, pkg-config]
       rpc: [libtirpc]

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

@@ -307,7 +307,7 @@ class Openmpi(AutotoolsPackage):
     depends_on('knem', when='fabrics=knem')
 
     depends_on('lsf', when='schedulers=lsf')
-    depends_on('openpbs', when='schedulers=tm')
+    depends_on('pbs', when='schedulers=tm')
     depends_on('slurm', when='schedulers=slurm')
 
     depends_on('openssh', type='run')
@@ -588,7 +588,7 @@ def with_or_without_lsf(self, activated):
     def with_or_without_tm(self, activated):
         if not activated:
             return '--without-tm'
-        return '--with-tm={0}'.format(self.spec['openpbs'].prefix)
+        return '--with-tm={0}'.format(self.spec['pbs'].prefix)
 
     @run_before('autoreconf')
     def die_without_fortran(self):

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

@@ -0,0 +1,37 @@
+# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Torque(Package):
+    """TORQUE (Terascale Open-source Resource and QUEue Manager) is an open
+    source project based on the original PBS resource manager developed by NASA,
+    LLNL, and MRJ."""
+
+    homepage = "https://github.com/abarbu/torque"
+    has_code = False
+
+    maintainers = ['sethrj']
+
+    version('3.0.4')
+    version('3.0.2')
+
+    provides('pbs')
+
+    # TORQUE needs to be added as an external package to SPACK. For this, the
+    # config file packages.yaml needs to be adjusted:
+    #
+    # packages:
+    #   torque:
+    #     buildable: False
+    #     externals:
+    #     - spec: torque@3.0.2
+    #       prefix: /opt/torque (path to your TORQUE installation)
+
+    def install(self, spec, prefix):
+        raise InstallError(
+            self.spec.format('{name} is not installable, you need to specify '
+                             'it as an external package in packages.yaml'))