Pierre-Sassoulas
commented
2 years ago Thank you for opening the bug. This is quite an upgrade you did there !
Closed davekirby closed 2 years ago
Pierre-Sassoulas
commented
2 years ago Thank you for opening the bug. This is quite an upgrade you did there !
DanielNoord
commented
2 years ago The following diff would fix this issue:
diff --git a/pylint/checkers/typecheck.py b/pylint/checkers/typecheck.py
index bb9c3de52..25837c343 100644
--- a/pylint/checkers/typecheck.py
+++ b/pylint/checkers/typecheck.py
@@ -1087,6 +1087,8 @@ accessed. Python regular expressions are accepted.",
continue
missingattr.add((owner, name))
continue
+ except astroid.InferenceError:
+ continue
# stop on the first found
break
else:However, I'd like to investigate if we can't prevent this InferenceError. It seems this might be preventable. Similarly, we might want to add the try...except to getattr in astroid instead of pylint as getattr does not really reflect that it using inference and that it should be guarded by an except.
DanielNoord
commented
2 years ago I'm trying to narrow down the issue. I think I have found a solution that goes beyond catching the exception, but I wonder if my new fix isn't masking a deeper issue.
@davekirby I got the reproducible example down to:
from sqlalchemy.sql.expression import FunctionElement
def compile_concat_for_postgresql(compiler, **kw):
"""Implementation of compat for PostgreSQL."""
return f"compat({compiler.process(**kw)})"
class months_between(FunctionElement):
"""Amount of months between two dates represented as integer value."""
def __init__(self):
super().__init__()I don't really understand why compile_concat_for_postgresql is necessary for this to crash. I have no experience with sqlalchemy and I grepped for the function name but couldn't find anything. Could you try and explain what the function does? I don't immediately see why its definition interferes with astroid's inference of months_between but it seems to have some effect...
DanielNoord
commented
2 years ago Brought the reproducible example down to:
test.py:
from sqlalchemy.sql import roles
from test2 import FromClause
class HasMemoized(object):
...
class Generative(HasMemoized):
...
class ColumnElement(
roles.ColumnArgumentOrKeyRole,
roles.BinaryElementRole,
roles.OrderByRole,
roles.ColumnsClauseRole,
roles.LimitOffsetRole,
roles.DMLColumnRole,
roles.DDLConstraintColumnRole,
roles.StatementRole,
Generative,
):
...
class FunctionElement(ColumnElement, FromClause):
...
class months_between(FunctionElement):
"""Amount of months between two dates represented as integer value."""
def __init__(self):
super().__init__()test2.py:
from operator import attrgetter
from sqlalchemy.sql import roles
class HasCacheKey(object):
...
class HasMemoized(object):
...
class MemoizedHasCacheKey(HasCacheKey, HasMemoized):
...
class ClauseElement(MemoizedHasCacheKey):
...
class ReturnsRows(roles.ReturnsRowsRole, ClauseElement):
...
class Selectable(ReturnsRows):
...
class FromClause(roles.AnonymizedFromClauseRole, Selectable):
c = property(attrgetter("columns"))sqlalchemy.sql.roles:
from operator import attrgetter
from sqlalchemy.sql import roles
class HasCacheKey(object):
...
class HasMemoized(object):
...
class MemoizedHasCacheKey(HasCacheKey, HasMemoized):
...
class ClauseElement(MemoizedHasCacheKey):
...
class ReturnsRows(roles.ReturnsRowsRole, ClauseElement):
...
class Selectable(ReturnsRows):
...
class FromClause(roles.AnonymizedFromClauseRole, Selectable):
c = property(attrgetter("columns"))I believe the issue is related to the imports in roles. There are probably too many ancestors for the cache and therefore astroid trips up.
DanielNoord
commented
2 years ago I have found a fix and submitted a PR to astroid. I expect it to land in 2.10 which I hope we can release before pylint 2.13 is released.
Bug description
After upgrading pylint from 2.2.2 to 2.12.2 and astroid from 2.1.0 to 2.9.3, a file that contained sqlalchemy user function definitions caused pylint to crash with an InferenceError exception. I have cut the file down to the example code below, and it still crashes. Curiously if you remove either the FunctionElement subclass OR the expression.compiles decorator it works, even though they are completely separate bits of code.
Command used
Pylint output
Expected behavior
Pylint to run to completion and report any errors in the file.
Pylint version
OS / Environment
RHEL 8
Additional dependencies
SQLAlchemy==1.4.29