libcatalyst: add package (#23595)

There are no official releases yet, so just use a git snapshot for now.

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

@@ -0,0 +1,40 @@
+# 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 Libcatalyst(CMakePackage):
+    """Catalyst is an API specification developed for simulations (and other
+    scientific data producers) to analyze and visualize data in situ."""
+
+    homepage = 'https://gitlab.kitware.com/paraview/catalyst'
+    url      = "https://gitlab.kitware.com/paraview/catalyst/-/archive/{0}/catalyst-{0}.tar.bz2"
+
+    maintainers = ['mathstuf']
+
+    # master as of 2021-05-12
+    version('8456ccd6015142b5a7705f79471361d4f5644fa7', sha256='5a01f12b271d9d9e9b89f31d45a5f4b8426904483639d38754893adfd3547bab')
+
+    variant('mpi', default=False, description='Enable MPI support')
+    variant('python3', default=False, description='Enable Python3 support')
+
+    depends_on('mpi', when='+mpi')
+
+    # TODO: catalyst doesn't support an external conduit
+    # depends_on('conduit')
+
+    def url_for_version(self, version):
+        _urlfmt  = self.url
+        return _urlfmt.format(version)
+
+    def cmake_args(self):
+        """Populate cmake arguments for libcatalyst."""
+        args = [
+            '-DCATALYST_BUILD_TESTING=OFF',
+            self.define_from_variant('CATALYST_USE_MPI', 'mpi')
+        ]
+
+        return args