Issue 30626: "SystemError: <class '_io.TextIOWrapper'> returned NULL without setting an error" from open function (original) (raw)

Created on 2017-06-10 18:53 by ppperry, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Messages (7)
msg295654 - (view)	Author: (ppperry)	Date: 2017-06-10 18:57
This code (reduced from an example I had of trying to debug code including the module-level code of already imported modules), raises a SystemError: import builtins from importlib.machinery import PathFinder from importlib.util import find_spec import importlib import sys import _imp dct={} def copy_module(module): new = type(sys)(module.__name__) new.__dict__.update(module.__dict__) return new dct["__builtins__"] = b = copy_module(builtins) spec = PathFinder.find_spec("_bootstrap",importlib.__path__) source_bootstrap = type(sys)("_bootstrap"); spec.loader.exec_module(source_bootstrap); source_bootstrap.__name__ = "importlib._bootstrap"; new_sys = copy_module(sys) new_sys.path_hooks = [] new_sys.meta_path = [] new_sys.modules = { "importlib._bootstrap":source_bootstrap, "importlib._bootstrap_external":importlib._bootstrap_external, } b.__import__ = source_bootstrap.__import__ source_bootstrap._install(new_sys,_imp) dct["__file__"]=__file__ exec("open(__file__)",dct) The actual file passed to the open function doesn't matter, as long as it would work
msg295680 - (view)	Author: Alyssa Coghlan (ncoghlan) *	Date: 2017-06-11 01:48
I couldn't reproduce this on 3.7, but I can confirm that 3.6 gives a SystemError with the above code: $ ./python _issue30626.py Traceback (most recent call last): File "_issue30626.py", line 30, in exec("open(__file__)",dct) File "", line 1, in SystemError: <class '_io.TextIOWrapper'> returned NULL without setting an error It's plausible this was fixed as part of the interpreter startup refactoring, so I doubt we're going to able to easily isolate the specific change that fixed it :(
msg295681 - (view)	Author: Alyssa Coghlan (ncoghlan) *	Date: 2017-06-11 01:49
That said: given that we know it *is* fixed somewhere in 3.7, it would likely be useful to check the assumption that the startup refactoring fixed it by going to the last commit before that landed and seeing if the error still occurs.
msg295693 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-06-11 08:16
In rare circumstances PyImport_Import() could return NULL without raising an error. It *isn't* fixed in 3.7.
msg296118 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-06-15 17:54
New changeset 145541cfa05394c38cfd64c0be2c5fb382860995 by Serhiy Storchaka in branch 'master': bpo-30626: Fix error handling in PyImport_Import(). (#2103) https://github.com/python/cpython/commit/145541cfa05394c38cfd64c0be2c5fb382860995
msg296119 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-06-15 18:15
New changeset fab05de21480fc54a5101cf813195cb32724b5ad by Serhiy Storchaka in branch '3.6': [3.6] bpo-30626: Fix error handling in PyImport_Import(). (GH-2103) (#2221) https://github.com/python/cpython/commit/fab05de21480fc54a5101cf813195cb32724b5ad
msg296120 - (view)	Author: Serhiy Storchaka (serhiy.storchaka) *	Date: 2017-06-15 18:15
New changeset 263dcc39daa74066c2b2fcb007a4bd4f7ec65073 by Serhiy Storchaka in branch '3.5': [3.5] bpo-30626: Fix error handling in PyImport_Import(). (GH-2103) (#2222) https://github.com/python/cpython/commit/263dcc39daa74066c2b2fcb007a4bd4f7ec65073