[issue45108] frame.f_lasti points at DICT_MERGE instead of CALL_FUNCTION_EX in Windows only
New submission from Alex Hall :
In this script:
import inspect
import dis
def foo(**_):
frame = inspect.currentframe().f_back
print(frame.f_lasti)
dis.dis(frame.f_code)
d = {'a': 1, 'b': 2}
foo(**d)
dis shows these instructions for `foo(**d)`:
10 34 LOAD_NAME2 (foo)
36 BUILD_TUPLE 0
38 BUILD_MAP0
40 LOAD_NAME3 (d)
42 DICT_MERGE 1
44 CALL_FUNCTION_EX 1
46 POP_TOP
48 LOAD_CONST 1 (None)
50 RETURN_VALUE
On Linux/OSX, frame.f_lasti is 44, pointing to the CALL_FUNCTION_EX as I'd
expect.
But on Windows it's 42, which is the preceding instruction DICT_MERGE.
The bytecode itself is identical on the different systems, it's just the frame
offset that differs.
This manifested as a test failure in a debugging tool here:
https://github.com/samuelcolvin/python-devtools/pull/93
--
components: Interpreter Core, Windows
messages: 401098
nosy: alexmojaki, paul.moore, steve.dower, tim.golden, zach.ware
priority: normal
severity: normal
status: open
title: frame.f_lasti points at DICT_MERGE instead of CALL_FUNCTION_EX in
Windows only
type: behavior
versions: Python 3.10, Python 3.9
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[issue44576] AttributeError: incorrect line identified in Python 3.10
Alex Hall added the comment: (meant to say "so I'm pulling in @Mark.Shannon) -- ___ Python tracker <https://bugs.python.org/issue44576> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue44576] AttributeError: incorrect line identified in Python 3.10
Alex Hall added the comment: I believe this is the outcome of https://bugs.python.org/issue39316 which I filed, so I'm pulling in . Naturally I think the new behaviour is not a bug but a feature. I think it's more important for the traceback to show the attribute access (`two`) than the value (`one`). That's what the frame was doing at the time which led to the error. The difference becomes even more important when calling a method with no arguments. Given this script: class A: def b(self): 1 / 0 x = ( A() .b() ) The 3.9 traceback points to the line with `A()` in the `` frame, while 3.10 correctly points to `.b()`, which makes the following line 'in b' make more sense. Where the old behaviour has really gotten to me is when I run the pycharm debugger and put a breakpoint on the .b() line and it never gets hit. Not being sure what lines 'count', I sometimes defensively put breakpoints on a cluster of lines, then spend more time removing them later. Having that fixed in 3.10 is great. -- components: +Interpreter Core nosy: +Mark.Shannon, alexmojaki type: -> behavior ___ Python tracker <https://bugs.python.org/issue44576> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue44393] segfault with sys.setrecursionlimit
New submission from Alex Hall : Found on: Python 3.9.5 GCC 11.1 on Linux (x86_64) Reproduced on: Python 3.9.5 Clang 9.0.8 Linux (arm) When setting the recursion limit to a high enough amount, trying to reach that recursion limit ends in a segmentation fault (stack overflow?) code: ```py import sys def recurse(n: int) -> int: recurse(n) sys.setrecursionlimit(2**16-1) recurse(100) ``` -- components: Library (Lib) files: segpy.png messages: 395626 nosy: ultrabear priority: normal severity: normal status: open title: segfault with sys.setrecursionlimit type: crash versions: Python 3.9 Added file: https://bugs.python.org/file50104/segpy.png ___ Python tracker <https://bugs.python.org/issue44393> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue43121] Incorrect SyntaxError message for missing comma (3.10.a5)
Alex Hall added the comment: Pablo, check out https://github.com/aroberge/friendly/discussions/197, particularly the second bullet point which has a dataset of syntax errors. -- nosy: +alexmojaki ___ Python tracker <https://bugs.python.org/issue43121> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue39316] settrace skips lines when chaining methods without arguments
Alex Hall added the comment:
I just came across https://www.python.org/dev/peps/pep-0626/, seems like this
would need to be fixed to satisfy the PEP, but on the latest CPython it's not:
```
➜ ~ python3.10 ~/Downloads/trace_skipping_lines_bug.py
14 slug = "doing_the_thing"
15 print(slug
16 .replace("_", " ")
15 print(slug
19 .replace("a", "b")
15 print(slug
21 .replace("The ", "the "))
15 print(slug
doing the thing
➜ ~ python3.10 --version
Python 3.10.0a6+
➜ ~ python3.10
Python 3.10.0a6+ (heads/master:cd8dcbc, Mar 14 2021, 11:58:23) [GCC 7.5.0] on
linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
```
--
type: -> behavior
versions: +Python 3.10
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[issue39316] settrace skips lines when chaining methods without arguments
Change by Alex Hall : -- nosy: +Mark.Shannon ___ Python tracker <https://bugs.python.org/issue39316> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue41614] Items put on Queue in thread in child process sometimes not seen by parent process
New submission from Alex Hall : See attached file. The summary is that I start a Process, which starts a Thread, which puts some values on a Queue which was originally created by the parent process and passed down. Usually this works but occasionally the parent process doesn't see the items on the queue: queue.get() times out and queue.empty() is True, although queue.qsize() is accurate. I can reproduce this on master: Python 3.10.0a0 (heads/master:802726a, Aug 22 2020, 12:56:09) [GCC 7.5.0] on linux as well as other versions I have installed which I've selected. On 3.6 it seems like the problem is even worse and some of my comments don't apply. I've tested the script on Ubuntu 18.04.4, but the general problem seems to also happen on OSX although I can't confirm that now. -- files: queue_bug.py messages: 375795 nosy: alexmojaki priority: normal severity: normal status: open title: Items put on Queue in thread in child process sometimes not seen by parent process versions: Python 3.10, Python 3.6, Python 3.7, Python 3.8 Added file: https://bugs.python.org/file49422/queue_bug.py ___ Python tracker <https://bugs.python.org/issue41614> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue39816] More descriptive error message than "too many values to unpack"
New submission from Alex Hall : Based on the discussion in https://mail.python.org/archives/list/python-id...@python.org/thread/C6QEAEEAELUHMLB23OBRSQK2UYU3AF5O/ When unpacking fails with an error such as: ValueError: too many values to unpack (expected 2) the name of the type of the unpacked object should be included, e.g. ValueError: too many values to unpack (expected 2) from object of type 'str' and if the type is exactly list or tuple, which are already special cased: https://github.com/python/cpython/blob/baf29b221682be0f4fde53a05ea3f57c3c79f431/Python/ceval.c#L2243-L2252 then the length can also be included: ValueError: too many values to unpack (expected 2, got 3) from object of type 'tuple' -- components: Interpreter Core messages: 363083 nosy: alexmojaki priority: normal severity: normal status: open title: More descriptive error message than "too many values to unpack" type: enhancement versions: Python 3.9 ___ Python tracker <https://bugs.python.org/issue39816> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue39810] Generic script for finding bugs in get_source_segment
New submission from Alex Hall : Attached is a script which: - Gets all the source code it can find from sys.modules - Looks at every node in the parsed source - Gets source text for that node using ast.get_source_segment - Parses the source text again - Compares the original node with the newly parsed node - Points out if the nodes don't match I ran this on Python 3.8.0, and it found several issues which have now been solved. So if there was a test like this then many bugs would have been caught earlier. I haven't tried it on a build of master, so I'm actually not sure which bugs have been fixed and what new bugs have been introduced. The script partly relies on [asttokens](https://github.com/gristlabs/asttokens) which is another way to get the source code of a node. This helps to skip some known issues and to show what the output from get_source_segment should probably be. You don't strictly need to install asttokens to run the script but it's helpful. -- components: Interpreter Core files: get_source_segment_test.py messages: 363056 nosy: alexmojaki priority: normal severity: normal status: open title: Generic script for finding bugs in get_source_segment type: behavior versions: Python 3.8, Python 3.9 Added file: https://bugs.python.org/file48940/get_source_segment_test.py ___ Python tracker <https://bugs.python.org/issue39810> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13672] Add co_qualname attribute in code objects
Alex Hall added the comment: I think this would be very useful in tracebacks. If a traceback line had a more useful name like `MyClass.__init__` instead of just `__init__` or `my_decorator..wrapper` instead of just `wrapper` it would provide useful context to the frame. -- nosy: +alexmojaki ___ Python tracker <https://bugs.python.org/issue13672> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue33997] multiprocessing Pool hangs in terminate()
Alex Hall added the comment: Sorry, I should have looked around more, I think my problem is https://bugs.python.org/issue22393 -- ___ Python tracker <https://bugs.python.org/issue33997> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue33997] multiprocessing Pool hangs in terminate()
Alex Hall added the comment: I'm also experiencing hanging on terminate. I haven't made a debug build or anything but it's happening to me consistently on 3.8, although I haven't managed to create a small example to reproduce. Replacing pool.py with https://raw.githubusercontent.com/python/cpython/5f6a05bf5b3f7e3c1d805b3bbd8c5ad18f26d933/Lib/multiprocessing/pool.py (from the PR) did not help. So maybe what I'm experiencing is unrelated. It gets stuck on `inqueue._rlock.acquire()` in `Pool._help_stuff_finish`. I've attached debugging info from snoop, maybe that will help. -- nosy: +alexmojaki Added file: https://bugs.python.org/file48867/pool_terminate_snoop.txt ___ Python tracker <https://bugs.python.org/issue33997> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue39316] settrace skips lines when chaining methods without arguments
New submission from Alex Hall :
When stepping through a multiline expression like this:
```
print(slug
.replace("_", " ")
.title()
.upper()
.replace("a", "b")
.lower()
.replace("The ", "the "))
```
only these lines are hit by the tracer function:
15 print(slug
16 .replace("_", " ")
19 .replace("a", "b")
21 .replace("The ", "the "))
I'm guessing the problem is that there are no expressions on the other lines,
as the attributes and calls all start with slug.
--
components: Interpreter Core
files: trace_skipping_lines_bug.py
messages: 359878
nosy: alexmojaki
priority: normal
severity: normal
status: open
title: settrace skips lines when chaining methods without arguments
versions: Python 2.7, Python 3.5, Python 3.6, Python 3.7, Python 3.8, Python 3.9
Added file: https://bugs.python.org/file48837/trace_skipping_lines_bug.py
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[issue38535] Incorrect col_offset for decorators with zero arguments (empty parentheses)
Alex Hall added the comment: I assume this also happens on 3.9, it's just a bit hard for me to test that now. -- ___ Python tracker <https://bugs.python.org/issue38535> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue38535] Incorrect col_offset for decorators with zero arguments (empty parentheses)
New submission from Alex Hall : In a decorator such as `@a()`, the ast.Call node has a col_offset starting from the @ symbol. This doesn't happen for decorators without arguments (e.g. `@a`) or with some arguments (e.g. `@a(x)`). -- components: Interpreter Core files: decorator_python_bug.py messages: 354987 nosy: alexmojaki priority: normal severity: normal status: open title: Incorrect col_offset for decorators with zero arguments (empty parentheses) type: behavior versions: Python 2.7, Python 3.5, Python 3.6, Python 3.7, Python 3.8 Added file: https://bugs.python.org/file48669/decorator_python_bug.py ___ Python tracker <https://bugs.python.org/issue38535> ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
