"AssertionError: Cannot find component" for local namedtuple

[ghost]

Crash Report

mypy crashes when inheriting from a locally defined namedtuple, when all of the following is true:

• Its fields are not a literal
• Another file generates an attr-defined error
• Cache is enabled (without --no-incremental)

Seems to be related to #10913, but produces a traceback similar to the closed #7281.

Traceback

Traceback (most recent call last):
  File "/home/.../env/bin/mypy", line 8, in <module>
    sys.exit(console_entry())
  File "/home/.../env/lib/python3.7/site-packages/mypy/__main__.py", line 11, in console_entry
    main(None, sys.stdout, sys.stderr)
  File "mypy/main.py", line 87, in main
  File "mypy/main.py", line 165, in run_build
  File "mypy/build.py", line 179, in build
  File "mypy/build.py", line 254, in _build
  File "mypy/build.py", line 2697, in dispatch
  File "mypy/build.py", line 3014, in process_graph
  File "mypy/build.py", line 3092, in process_fresh_modules
  File "mypy/build.py", line 1991, in fix_cross_refs
  File "mypy/fixup.py", line 26, in fixup_module
  File "mypy/fixup.py", line 90, in visit_symbol_table
  File "mypy/fixup.py", line 49, in visit_type_info
  File "mypy/types.py", line 846, in accept
  File "mypy/fixup.py", line 154, in visit_instance
  File "mypy/fixup.py", line 269, in lookup_qualified_typeinfo
  File "mypy/fixup.py", line 297, in lookup_qualified
  File "mypy/fixup.py", line 306, in lookup_qualified_stnode
  File "mypy/lookup.py", line 47, in lookup_fully_qualified
AssertionError: Cannot find component 'TupleType@4' for 'a.TupleType@4'

To Reproduce

Use this script to reproduce:

#!/bin/sh

mkdir -p mypy_crash

cat >mypy_crash/a.py <<EOF
from collections import namedtuple

def crash(fields):
    TupleType = namedtuple("TupleType", fields)
    class InheritFromTuple(TupleType):
        pass
EOF

cat >mypy_crash/b.py <<EOF
from a import A
EOF

rm -rf .mypy_cache

echo "First run, should be ok"
mypy mypy_crash/
echo

echo "Second run, with cache disabled, should be ok"
mypy --no-incremental mypy_crash/
echo

echo "Third run, with cache enabled, this should crash"
mypy mypy_crash/

mypy does not crash if any of the following are removed:

• File b.py
• Import error in file b.py, e.g. by replacing from a import A by from a import crash (or any other valid name)
• Definition of class InheritFromTuple in a.py
• Argument fields in definition of namedtuple, e.g. by TupleType = namedtuple("TupleType", 'a b c')

Your Environment

• Mypy version used: 0.910
• Mypy command-line flags: (none, see script)
• Mypy configuration options from mypy.ini (and other config files): (none, can reproduce without mypy.ini)
• Python version used: 3.7.9
• Operating system and version: Ubuntu 18.04.6 LTS (bionic)