interpreter: use python dunders instead of lock for unpicklability

This simplifies things for us, as we don't have to have threading
imported for no other reason, and we can remove the
`an_unpicklable_object` from the Interpreter and mesonlib, since there
was only one user of this.

1 files changed, 4 insertions, 2 deletions

diff --git a/mesonbuild/interpreter/interpreter.py b/mesonbuild/interpreter/interpreter.py
index db4f9e9..c3e9b48 100644
--- a/mesonbuild/interpreter/interpreter.py
+++ b/mesonbuild/interpreter/interpreter.py
@@ -21,7 +21,7 @@ from .. import optinterpreter
 from .. import compilers
 from ..wrap import wrap, WrapMode
 from .. import mesonlib
-from ..mesonlib import HoldableObject, FileMode, MachineChoice, OptionKey, listify, extract_as_list, has_path_sep
+from ..mesonlib import MesonBugException, HoldableObject, FileMode, MachineChoice, OptionKey, listify, extract_as_list, has_path_sep
 from ..programs import ExternalProgram, NonExistingExternalProgram
 from ..dependencies import Dependency
 from ..depfile import DepFile
@@ -231,7 +231,6 @@ class Interpreter(InterpreterBase, HoldableObject):
                 is_translated: bool = False,
             ) -> None:
         super().__init__(_build.environment.get_source_dir(), subdir, subproject)
-        self.an_unpicklable_object = mesonlib.an_unpicklable_object
         self.build = _build
         self.environment = self.build.environment
         self.coredata = self.environment.get_coredata()
@@ -279,6 +278,9 @@ class Interpreter(InterpreterBase, HoldableObject):
             self.parse_project()
         self._redetect_machines()
 
+    def __getnewargs_ex__(self) -> T.Tuple[T.Tuple[object], T.Dict[str, object]]:
+        raise MesonBugException('This class is unpicklable')
+
     def _redetect_machines(self):
         # Re-initialize machine descriptions. We can do a better job now because we
         # have the compilers needed to gain more knowledge, so wipe out old