Merge pull request #618 from epfl-scitas/fixes/espresso_no_module

fix : no module file gets generated by espresso

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

@@ -32,6 +32,10 @@ def check_variants(self, spec):
         if '+elpa' in spec and ('~mpi' in spec or '~scalapack' in spec):
             raise RuntimeError(error.format(variant='elpa'))
 
+    def setup_environment(self, spack_env, run_env):
+        # Espresso copies every executable in prefix without creating sub-folders
+        run_env.prepend_path('PATH', self.prefix)
+
     def install(self, spec, prefix):
         self.check_variants(spec)