[!21] Change iteration variable names to avoid clashes with the rest of Spack

Merge branch 'bugfix/iteration-variables' into 'master'

ref:spack/dune-spack\> Spack's weird overall architecture makes temporary
variables in the package scope really dangerous. In my case, an iteration
variable 'module' caused the perl package to fall over\...

See merge request [spack/dune-spack!21]

  [spack/dune-spack!21]: gitlab.dune-project.org/spack/dune-spack/merge_requests/21

packages/dune/package.py

@@ -65,7 +65,7 @@ class Dune(CMakePackage):
     # Dependencies between modules - not necessarily the full set
     # as the closure of module dependencies is built later on.
     # dune-common does not need to be named.
-    module_dependencies = {
+    dune_module_dependencies = {
         'dune-alugrid': ['dune-grid'],
         'dune-codegen': ['dune-pdelab', 'dune-testtools', 'dune-alugrid'],
         'dune-fem': ['dune-grid'],
@@ -80,18 +80,22 @@ class Dune(CMakePackage):
         'dune-polygongrid': ['dune-grid'],
     }
 
-    # Build the closure of above module dependency list
+    # Build the closure of above module dependency list.
-    for module in module_dependencies:
+    # We need to use cryptic variable names here because
-        closure = set(module_dependencies[module])
+    # Spack behaves in weird ways if we accidentally use
-        old_closure = set()
+    # names (like 'module') that are used in seemingly
-        while (len(closure) > len(old_closure)):
+    # unrelated places.
-            old_closure = closure.copy()
+    for _mod in dune_module_dependencies:
+        _closure = set(dune_module_dependencies[_mod])
+        _old_closure = set()
+        while (len(_closure) > len(_old_closure)):
+            _old_closure = _closure.copy()
 
-            for res in old_closure:
+            for _res in _old_closure:
-                for mod in module_dependencies.get(res, []):
+                for _m in dune_module_dependencies.get(_res, []):
-                    closure.add(mod)
+                    _closure.add(_m)
 
-        module_dependencies[module] = list(closure)
+        dune_module_dependencies[_mod] = list(_closure)
 
     # Variants for the general build process
     variant('shared', default=True, description='Enables the build of shared libraries.')
@@ -116,119 +120,119 @@ class Dune(CMakePackage):
     # Define conflicts between Dune module variants. These conflicts are of the following type:
     # conflicts('dune~functions', when='+pdelab') -> dune-pdelab cannot be built without dune-functions
     for var, res in dune_variants_to_resources.items():
-        for dep in module_dependencies.get(res, []):
+        for dep in dune_module_dependencies.get(res, []):
             if dep in dune_resources_to_variants:
                 conflicts('dune~%s' % dune_resources_to_variants[dep], when='+%s' % var)
 
     # Iterate over all available Dune versions and define resources for all Dune modules
     # If a Dune module behaves differently for different versions (e.g. dune-python got
     # merged into dune-common post-2.7), define the resource outside of this loop.
-    for vers, branch in dune_versions_to_branch:
+    for _vers, _branch in dune_versions_to_branch:
-        version(vers, branch=branch)
+        version(_vers, branch=_branch)
 
         resource(
             name='dune-geometry',
             git='https://gitlab.dune-project.org/core/dune-geometry.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s' % vers,
+            when='@%s' % _vers,
         )
 
         resource(
             name='dune-grid',
             git='https://gitlab.dune-project.org/core/dune-grid.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s' % vers,
+            when='@%s' % _vers,
         )
 
         resource(
             name='dune-istl',
             git='https://gitlab.dune-project.org/core/dune-istl.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s' % vers,
+            when='@%s' % _vers,
         )
 
         resource(
             name='dune-localfunctions',
             git='https://gitlab.dune-project.org/core/dune-localfunctions.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s' % vers,
+            when='@%s' % _vers,
         )
 
         resource(
             name='dune-functions',
             git='https://gitlab.dune-project.org/staging/dune-functions.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+functions' % vers,
+            when='@%s+functions' % _vers,
         )
 
         resource(
             name='dune-typetree',
             git='https://gitlab.dune-project.org/staging/dune-typetree.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+typetree' % vers,
+            when='@%s+typetree' % _vers,
         )
 
         resource(
             name='dune-alugrid',
             git='https://gitlab.dune-project.org/extensions/dune-alugrid.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+alugrid' % vers,
+            when='@%s+alugrid' % _vers,
         )
 
         resource(
             name='dune-uggrid',
             git='https://gitlab.dune-project.org/staging/dune-uggrid.git',
-            branch='releases/2.7',
+            branch=_branch,
-            when='@%s+uggrid' % vers,
+            when='@%s+uggrid' % _vers,
         )
 
         resource(
             name='dune-spgrid',
             git='https://gitlab.dune-project.org/extensions/dune-spgrid.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+spgrid' % vers,
+            when='@%s+spgrid' % _vers,
         )
 
         resource(
             name='dune-testtools',
             git='https://gitlab.dune-project.org/quality/dune-testtools.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+testtools' % vers,
+            when='@%s+testtools' % _vers,
         )
 
         resource(
             name='dune-polygongrid',
             git='https://gitlab.dune-project.org/extensions/dune-polygongrid.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+polygongrid' % vers,
+            when='@%s+polygongrid' % _vers,
         )
 
         resource(
             name='dune-foamgrid',
             git='https://gitlab.dune-project.org/extensions/dune-foamgrid.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+foamgrid' % vers,
+            when='@%s+foamgrid' % _vers,
         )
 
         resource(
             name='dune-multidomaingrid',
             git='https://gitlab.dune-project.org/extensions/dune-multidomaingrid.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+multidomaingrid' % vers,
+            when='@%s+multidomaingrid' % _vers,
         )
 
         resource(
             name='dune-fem',
             git='https://gitlab.dune-project.org/dune-fem/dune-fem.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+fem' % vers,
+            when='@%s+fem' % _vers,
         )
 
         resource(
             name='dune-fempy',
             git='https://gitlab.dune-project.org/dune-fem/dune-fempy.git',
-            branch=branch,
+            branch=_branch,
-            when='@%s+fem+python' % vers,
+            when='@%s+fem+python' % _vers,
         )
 
     # The dune-grid-glue package does not yet have a 2.7-compatible release
@@ -304,9 +308,6 @@ class Dune(CMakePackage):
     # Apply patches
     patch('virtualenv_from_envvariable.patch', when='+testtools')
 
-    # Some additional variant conflicts of Dune modules and upstream dependencies
-    conflicts('dune~superlu', when='+codegen')
-
     def setup_build_environment(self, env):
         # We reset the DUNE_CONTROL_PATH here because any entries in this
         # path that contain Dune modules will break the Spack build process.