λ python -m mypy --config-file mypy_self_check.ini -p mypy --no-incremental
/Users/shantanu/dev/mypy/mypy/typeshed/stdlib/posixpath.pyi: error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 2.1.0+dev.0a72750b6d7f0f2dfaf65f49e63a74882c6b1108
Traceback (most recent call last):
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/Users/shantanu/dev/mypy/mypy/build_worker/__main__.py", line 6, in <module>
console_entry()
File "/Users/shantanu/dev/mypy/mypy/build_worker/worker.py", line 356, in console_entry
main(sys.argv[1:])
File "/Users/shantanu/dev/mypy/mypy/build_worker/worker.py", line 121, in main
serve(server, ctx)
File "/Users/shantanu/dev/mypy/mypy/build_worker/worker.py", line 220, in serve
load_states(mod_ids, graph, manager, scc_message.import_errors, scc_message.mod_data)
File "/Users/shantanu/dev/mypy/mypy/build_worker/worker.py", line 284, in load_states
state.parse_file(raw_data=raw_data)
File "/Users/shantanu/dev/mypy/mypy/build.py", line 3225, in parse_file
with self.wrap_context():
File "/Users/shantanu/Library/Application Support/uv/python/cpython-3.14.2-macos-aarch64-none/lib/python3.14/contextlib.py", line 162, in __exit__
self.gen.throw(value)
File "/Users/shantanu/dev/mypy/mypy/build.py", line 3077, in wrap_context
yield
File "/Users/shantanu/dev/mypy/mypy/build.py", line 3233, in parse_file
self.parse_file_inner(source, raw_data)
~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
File "/Users/shantanu/dev/mypy/mypy/build.py", line 3197, in parse_file_inner
self.tree = self.manager.parse_file(
~~~~~~~~~~~~~~~~~~~~~~~^
self.id, self.xpath, source, options=self.options, raw_data=raw_data
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
)
^
File "/Users/shantanu/dev/mypy/mypy/build.py", line 1294, in parse_file
tree = load_from_raw(path, id, raw_data, self.errors, options)
File "/Users/shantanu/dev/mypy/mypy/parse.py", line 80, in load_from_raw
defs = read_statements(state, data, n)
File "/Users/shantanu/dev/mypy/mypy/nativeparse.py", line 242, in read_statements
stmt = read_statement(state, data)
File "/Users/shantanu/dev/mypy/mypy/nativeparse.py", line 431, in read_statement
_read_and_set_import_metadata(data, stmt)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
File "/Users/shantanu/dev/mypy/mypy/nativeparse.py", line 2022, in _read_and_set_import_metadata
flags = read_int(data)
File "/Users/shantanu/dev/mypy/mypy/cache.py", line 368, in read_int
assert read_tag(data) == LITERAL_INT
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError
/Users/shantanu/dev/mypy/mypy/typeshed/stdlib/posixpath.pyi: note: use --pdb to drop into pdb
error: INTERNAL ERROR -- Please try using mypy master on GitHub:
https://mypy.readthedocs.io/en/stable/common_issues.html#using-a-development-mypy-build
Please report a bug at https://github.com/python/mypy/issues
version: 2.1.0+dev.0a72750b6d7f0f2dfaf65f49e63a74882c6b1108
Traceback (most recent call last):
File "/Users/shantanu/dev/mypy/mypy/build.py", line 1392, in receive_worker_message
return receive(self.workers[idx].conn)
File "/Users/shantanu/dev/mypy/mypy/ipc.py", line 481, in receive
raise OSError("No data received")
OSError: No data received
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "<frozen runpy>", line 198, in _run_module_as_main
File "<frozen runpy>", line 88, in _run_code
File "/Users/shantanu/dev/mypy/mypy/__main__.py", line 52, in <module>
console_entry()
File "/Users/shantanu/dev/mypy/mypy/__main__.py", line 16, in console_entry
main()
~~~~^^
File "/Users/shantanu/dev/mypy/mypy/main.py", line 154, in main
res, messages, blockers = run_build(sources, options, fscache, t0, stdout, stderr)
~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/Users/shantanu/dev/mypy/mypy/main.py", line 244, in run_build
res = build.build(sources, options, None, flush_errors, fscache, stdout, stderr)
File "/Users/shantanu/dev/mypy/mypy/build.py", line 422, in build
result = build_inner(
sources,
...<9 lines>...
metastore,
)
File "/Users/shantanu/dev/mypy/mypy/build.py", line 537, in build_inner
graph = dispatch(sources, manager, stdout, connect_threads)
File "/Users/shantanu/dev/mypy/mypy/build.py", line 4150, in dispatch
process_graph(graph, manager)
~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
File "/Users/shantanu/dev/mypy/mypy/build.py", line 4618, in process_graph
done, still_working, results = manager.wait_for_done(graph)
~~~~~~~~~~~~~~~~~~~~~^^^^^^^
File "/Users/shantanu/dev/mypy/mypy/build.py", line 1488, in wait_for_done
return self.wait_for_done_workers(graph)
~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^
File "/Users/shantanu/dev/mypy/mypy/build.py", line 1507, in wait_for_done_workers
buf = self.receive_worker_message(idx)
File "/Users/shantanu/dev/mypy/mypy/build.py", line 1400, in receive_worker_message
raise OSError(
f"Worker {idx} disconnected before sending data ({exit_status})"
) from exc
OSError: Worker 0 disconnected before sending data (exit code 2)
Currently if you have
ast_serialize==0.2installed and you try to type check mypy, you get a slightly confusing: