only build PETSc with Python support if Python is included as a non-b…

…uild dependency

easybuild/easyblocks/p/petsc.py

@@ -58,6 +58,8 @@ def __init__(self, *args, **kwargs):
         self.prefix_lib = ''
         self.prefix_bin = ''
 
+        self.with_python = False
+
         if self.cfg['sourceinstall']:
             self.prefix_inc = self.petsc_subdir
             self.prefix_lib = os.path.join(self.petsc_subdir, self.petsc_arch)
@@ -89,6 +91,17 @@ def make_builddir(self):
 
         super(EB_PETSc, self).make_builddir()
 
+    def prepare_step(self, *args, **kwargs):
+        """Prepare build environment."""
+
+        super(EB_PETSc, self).prepare_step(*args, **kwargs)
+
+        # build with Python support if Python is loaded as a non-build (runtime) dependency
+        build_deps = self.cfg.dependencies(build_only=True)
+        if get_software_root('Python') and not any(x['name'] == 'Python' for x in build_deps):
+            self.with_python = True
+            self.log.info("Python included as runtime dependency, so enabling Python support")
+
     def configure_step(self):
         """
         Configure PETSc by setting configure options and running configure script.
@@ -155,7 +168,7 @@ def configure_step(self):
                                          papi_inc_file, papi_lib)
 
             # Python extensions_step
-            if get_software_root('Python'):
+            if self.with_python:
 
                 # enable numpy support, but only if numpy is available
                 (_, ec) = run_cmd("python -c 'import numpy'", log_all=True, simple=False)
@@ -360,7 +373,7 @@ def sanity_check_step(self):
             custom_paths['dirs'].append(os.path.join(self.prefix_lib, 'lib', 'petsc', 'conf'))
 
         custom_commands = []
-        if get_software_root('Python'):
+        if self.with_python:
             custom_commands.append("python -m PetscBinaryIO --help")
 
         super(EB_PETSc, self).sanity_check_step(custom_paths=custom_paths, custom_commands=custom_commands)