[openloops][vbfnlo] Fix recipes and updated dependencies (#24461)

* [vbfnlo] Add doc variant to toggle building of docs

* [openloops] Add scons to dependencies

Make sure that the build_processes does not accidentally pick up a
non-suitable scons version from the underlying system

* [openloops] Set OLPYTHON to make sure the right scons is picked

* [openloops] Fix Flake8 style complaints

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

@@ -114,6 +114,16 @@ def configure(self, spec, prefix):
         elif self.spec.satisfies('@2.1.2:2.99.99 processes=lcg.coll'):
             copy(join_path(os.path.dirname(__file__), 'sft3.coll'), 'lcg.coll')
 
+    def setup_build_environment(self, env):
+        # Make sure that calling openloops picks up the scons that is shipped
+        # instead of falling back to a potentially unsuitable system version
+        env.set('OLPYTHON', self.spec['python'].prefix.bin.python)
+
+    def setup_run_environment(self, env):
+        # Make sure that calling openloops picks up the scons that is shipped
+        # instead of falling back to a potentially unsuitable system version
+        env.set('OLPYTHON', self.spec['python'].prefix.bin.python)
+
     def build(self, spec, prefix):
         scons = Executable('./scons')
         scons('generator=1', 'compile=2')

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

@@ -26,6 +26,12 @@ class Vbfnlo(AutotoolsPackage):
     version('2.7.1',      sha256='13e33d73d8a8ef64094621f87e6f94e01712e76cc19a86298d0b52cfcb9decca', preferred=True)
     # version('2.7.0',      sha256='0e96c0912599e3000fffec5305700b947b604a7b06c7975851503f445311e4ef')
 
+    # Documentation is broken on some systems:
+    # See https://github.com/vbfnlo/vbfnlo/issues/2
+    variant('doc', default=False,
+            description='Build documentation')
+    patch('vbfnlo_no_docs.patch', when='~doc')
+
     depends_on('hepmc')
     depends_on('gsl')
     depends_on('lhapdf')

var/spack/repos/builtin/packages/vbfnlo/vbfnlo_no_docs.patch

@@ -0,0 +1,13 @@
+diff --git a/Makefile.am b/Makefile.am
+index e3cfec3..ebf48f4 100644
+--- a/Makefile.am
++++ b/Makefile.am
+@@ -5,7 +5,7 @@ SUBDIRS = include \
+           loops \
+           amplitudes \
+           phasespace \
+-          lib src doc \
++          lib src \
+           regress
+ 
+ ACLOCAL_AMFLAGS = -I m4