BF: Handle build variants in tests

manifest_rules/test_environment.py

@@ -42,7 +42,17 @@ def preprocess_environment(envfile, condadir, regen_envfile=False):
                 f.write(f' - {p}\n')
 
     for i, pkg in enumerate(packages):
-        pkg, ver    = pkg.split()
+        # package specs are of the form
+        #     <package> <version>
+        # or
+        #     <package> <version> <variant>
+        #
+        # and are transformed into the form
+        #     <package>=<version>
+        # or
+        #     <package>=<version>=<variant>
+        pkg, ver    = pkg.split(maxsplit=2)
+        ver         = ver.replace(' ', '=')
         packages[i] = f'{pkg}={ver}'
 
     return packages