Crash at startup on Python 3.14 Fedora 43 beta arm64

[zuzzurro]

Problem

Running beets crashes at start

$ beet 

Led to this problem:

Traceback (most recent call last):
  File "/usr/bin/beet", line 5, in <module>
    from beets.ui import main
  File "/usr/lib/python3.14/site-packages/beets/ui/__init__.py", line 858, in <module>
    indent_str, left, right, separator=" -> ", max_width=term_width()
                                                         ~~~~~~~~~~^^
  File "/usr/lib/python3.14/site-packages/beets/ui/__init__.py", line 715, in term_width
    buf = fcntl.ioctl(0, termios.TIOCGWINSZ, " " * 4)
SystemError: buffer overflow

Here's a link to the music files that trigger the bug (if relevant):

Setup

• OS: Fedora 43 Beta arm64
• Python version: Python 3.14.0rc3
• beets version: beets-2.4.0-2.fc43.noarch
• Turning off plugins made problem go away (yes/no): no

My configuration (output of beet config) is:

empty configuration

[semohr]

We are not even supporting python 3.13 fully. You may want to downgrade your python version.

[zuzzurro]

Yeah. I thought it might be an arm64 specific issue, but then I realized that 1) 3.14 is not supported yet and 2) it also happens on Fedora 43 x64. So, I guess it rightly goes into the 3.14 support pile

[mbaldessari]

It happens on x86_64 as well. This fixed it for me:

diff --git a/beets/ui/__init__.py b/beets/ui/__init__.py
index e0c1bb486..a390da482 100644
--- a/beets/ui/__init__.py
+++ b/beets/ui/__init__.py
@@ -712,7 +712,7 @@ def term_width():
         return fallback

     try:
-        buf = fcntl.ioctl(0, termios.TIOCGWINSZ, " " * 4)
+        buf = fcntl.ioctl(0, termios.TIOCGWINSZ, b"\x00" * 8)
     except OSError:
         return fallback
     try:

(am currently traveling, so won't have time to submit a proper PR with testing for a couple of weeks)

[ajslater]

Additionally, Beets relies on the Confuse library and Confuse does not support Python 3.14 beetbox/confuse#176

[zuzzurro]

It happens on x86_64 as well. This fixed it for me:

diff --git a/beets/ui/__init__.py b/beets/ui/__init__.py
index e0c1bb486..a390da482 100644
--- a/beets/ui/__init__.py
+++ b/beets/ui/__init__.py
@@ -712,7 +712,7 @@ def term_width():
         return fallback

     try:
-        buf = fcntl.ioctl(0, termios.TIOCGWINSZ, " " * 4)
+        buf = fcntl.ioctl(0, termios.TIOCGWINSZ, b"\x00" * 8)
     except OSError:
         return fallback
     try:

(am currently traveling, so won't have time to submit a proper PR with testing for a couple of weeks)

I don't quite understand the reason for this regression, do you? Looking at the python code behind that call it doesn't seem to have changed recently. What doubled the required space needed to get a proper answer? (I'm not a python programmer and therefore I can just guess it's a space issue, also because of the "buffer overflow" error returned...)

[mbaldessari]

The crash is probably due to python 3.14 having added python/cpython@c2eaeee . The code was never 100% correct to begin with. The linked PR moves things to shutil and that should do it as well.

[sakgoyal]

confuse has a new release now which adds support for 3.13/3.14.