options: do not raise exception for unknown options in -U command

Fixes: #14956
Signed-off-by: Paolo Bonzini <[email protected]>

Author: bonzini

mesonbuild/options.py

@@ -1117,6 +1117,9 @@ def set_from_configure_command(self, D_args: T.Dict[OptionKey, T.Optional[str]])
                 del self.augments[key]
                 dirty = True
             else:
+                if key not in self.options:
+                    raise MesonException(f"Unknown option: {key}")
+
                 # TODO: For project options, "dropping an augment" means going
                 # back to the superproject's value.  However, it's confusing
                 # that -U does not simply remove the option from the stored

unittests/optiontests.py

@@ -331,6 +331,11 @@ def test_reconfigure_b_nonexistent(self):
         optstore = OptionStore(False)
         optstore.set_from_configure_command({OptionKey('b_ndebug'): True})
 
+    def test_unconfigure_nonexistent(self):
+        optstore = OptionStore(False)
+        with self.assertRaises(MesonException):
+            optstore.set_from_configure_command({OptionKey('nonexistent'): None})
+
     def test_subproject_proj_opt_with_same_name(self):
         name = 'tests'
         subp = 'subp'