plumed: fixed compilation on rhel6 (#4318)

* plumed: fixed compilation on rhel6 with mvapich2 and gcc@5.4.0 (#77)

* plumed: prevent parallel compilation, as it breaks for the newest version

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

@@ -113,6 +113,8 @@ class Plumed(AutotoolsPackage):
 
     force_autoreconf = True
 
+    parallel = False
+
     def apply_patch(self, other):
         plumed = subprocess.Popen(
             [join_path(self.spec.prefix.bin, 'plumed'), 'patch', '-p'],
@@ -126,7 +128,7 @@ def apply_patch(self, other):
 
     def setup_dependent_package(self, module, dependent_spec):
         # Make plumed visible from dependent packages
-        module.plumed = self.spec['plumed'].command
+        module.plumed = dependent_spec['plumed'].command
 
     @run_before('autoreconf')
     def filter_gslcblas(self):
@@ -162,6 +164,14 @@ def configure_args(self):
                     'STATIC_LIBS=-mt_mpi'
                 ])
 
+        # Set flags to help find gsl
+        if '+gsl' in self.spec:
+            gsl_libs = self.spec['gsl'].libs
+            blas_libs = self.spec['blas'].libs
+            configure_opts.append('LDFLAGS={0}'.format(
+                (gsl_libs + blas_libs).ld_flags
+            ))
+
         # Additional arguments
         configure_opts.extend([
             '--enable-shared={0}'.format('yes' if '+shared' in spec else 'no'),