Daemon crash: comparing tuple and None #7834
Description
In encountered a mypy daemon crash (when using dmypy suggest, not sure if it's related):
Traceback (most recent call last):
File "mypy/suggestions.py", line 212, in restore_after
File "mypy/suggestions.py", line 187, in suggest
File "mypy/suggestions.py", line 355, in get_suggestion
File "mypy/suggestions.py", line 325, in find_best
File "mypy/suggestions.py", line 524, in try_type
File "mypy/server/update.py", line 275, in trigger
File "mypy/server/update.py", line 804, in propagate_changes_using_dependencies
File "mypy/server/update.py", line 951, in reprocess_nodes
File "mypy/server/astdiff.py", line 160, in snapshot_symbol_table
File "mypy/server/astdiff.py", line 174, in snapshot_definition
File "mypy/server/astdiff.py", line 231, in snapshot_type
File "mypy/types.py", line 1061, in accept
File "mypy/server/astdiff.py", line 302, in visit_callable_type
File "mypy/server/astdiff.py", line 242, in snapshot_types
File "mypy/server/astdiff.py", line 231, in snapshot_type
File "mypy/types.py", line 1681, in accept
File "mypy/server/astdiff.py", line 325, in visit_union_type
TypeError: '<' not supported between instances of 'tuple' and 'NoneType'
It seems possible that type snapshots contain None values, which breaks sorting.
I don't have a repro, but the traceback may contain enough hints to fix the issue.