src/sage/doctest/control.py: Add available package systems to optional tags

Author: Matthias Koeppe

src/sage/doctest/control.py

@@ -363,6 +363,9 @@ def __init__(self, options, args):
                         if pkg['installed'] and pkg['installed_version'] == pkg['remote_version']:
                             options.optional.add(pkg['name'])
 
+                from sage.features import package_systems
+                options.optional.update(system.name for system in package_systems())
+
                 # Check that all tags are valid
                 for o in options.optional:
                     if not optionaltag_regex.search(o):