TypeError: 'gi._gi.GPropsIter' object is not iterable

[carlosal1015]

Describe the bug

When I start the program with python 3.13 we have the following error

$ pympress 
Traceback (most recent call last):
  File "/usr/lib/python3.13/site-packages/pympress/app.py", line 164, in do_activate
    self.gui = ui.UI(self, self.config)
               ~~~~~^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/pympress/ui.py", line 212, in __init__
    self.load_ui('presenter')
    ~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/pympress/builder.py", line 186, in load_ui
    self.__translate_widget_strings(obj)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^
  File "/usr/lib/python3.13/site-packages/pympress/builder.py", line 79, in __translate_widget_strings
    for str_prop in (prop.name for prop in a_widget.props if prop.value_type == GObject.TYPE_STRING):
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/pympress/builder.py", line 79, in <genexpr>
    for str_prop in (prop.name for prop in a_widget.props if prop.value_type == GObject.TYPE_STRING):
                                           ^^^^^^^^^^^^^^
TypeError: 'gi._gi.GPropsIter' object is not iterable

To Reproduce
Steps to reproduce the behavior:

1. Start pympress from terminal.

Expected behavior

Open the gui.

Environment (please complete the following information):

• OS: Arch Linux
• Python version: 3.13.1
• Pympress version: 1.8.5-2
• Installation method: https://aur.archlinux.org/packages/python-pympress

[Cimbali]

The properties iterator is not iterable… that’s interesting. Can you share the 2 first lines of your log file? It should give all the detailed versions of dependencies – Gtk etc.

[carlosal1015]

I am not sure where is located the log file, over ~/.config no directory called pympress.

➜  ~ pacman -Qi python-pympress 
Name            : python-pympress
Version         : 1.8.5-2
Description     : Simple and powerful dual-screen PDF reader designed for presentations
Architecture    : any
URL             : https://github.com/Cimbali/pympress
Licenses        : GPL-2.0-or-later
Groups          : None
Provides        : None
Depends On      : poppler-glib  gtk3  python-cairo  gdk-pixbuf2  python-gobject  gobject-introspection  python-watchdog  perl-x11-protocol  perl-net-dbus
Optional Deps   : vlc: for playing videos [installed]
                  python-vlc: for playing videos
                  gstreamer: for playing videos [installed]
                  gst-plugin-gtk: for playing videos
Required By     : None
Optional For    : None
Conflicts With  : None
Replaces        : None
Installed Size  : 823.82 KiB
Packager        : Unknown Packager
Build Date      : Sun 22 Dec 2024 03:40:14 PM -05
Install Date    : Sun 22 Dec 2024 04:28:39 PM -05
Install Reason  : Explicitly installed
Install Script  : No
Validated By    : None

• poppler-glib 24.11.0-2
• gtk3 1:3.24.43-4
• python-cairo 1.27.0-2
• gdk-pixbuf2 2.42.12-2
• python-gobject 3.50.0-2
• gobject-introspection 1.82.0-2
• python-watchdog 3.0.0-2
• perl-x11-protocol 0.56-16
• perl-net-dbus 1.2.0-7
• vlc 3.0.21-9
• gstreamer 1.24.10-2

[Cimbali]

Logs should be under ~/.cache but you've already given all the info I was looking for. Will try to reproduce

[carlosal1015]

Yes, there is ~/.cache/pympress.log .

pympress.log

[carlosal1015]

Logs should be under ~/.cache but you've already given all the info I was looking for. Will try to reproduce

With docker is easy to reproduce

$ docker run -it --rm archlinux:base-devel
useradd -l -md /home/aur -s /bin/bash aur
passwd -d aur
echo 'aur ALL=(ALL) ALL' > /etc/sudoers.d/aur
pacman --noconfirm -Syu git xorg-server-xvfb
su aur
cd ~
git clone https://aur.archlinux.org/python-pympress.git
cd python-pympress
makepkg --noconfirm -si
sudo Xvfb :5 &
DISPLAY=:5 pympress
cat ~/.cache/pympress.log

[Cimbali]

Ok this is technically a bug in GPropsIter which is missing its required __iter__ function (it only has __next__). I’d prefer to see it fixed upstream rather than add a workaround in code, as that would also not be guaranteed to be future-proof.

Temporary fixes are:

• use python ≤ 3.12
• change line 79 in builder.py as follows:

  --- i/pympress/builder.py
  +++ w/pympress/builder.py
  @@ -76,7 +76,7 @@ class Builder(Gtk.Builder):
           Args:
               a_widget (:class:`~GObject.Object`): an object built by the builder, usually a widget
           """
  -        for str_prop in (prop.name for prop in a_widget.props if prop.value_type == GObject.TYPE_STRING):
  +        for str_prop in (prop.name for prop in list(a_widget.props) if prop.value_type == GObject.TYPE_STRING):
               try:
                   str_val = getattr(a_widget.props, str_prop)
                   if str_val:

(i.e. don’t rely on the conversion to an iterator.)

This patch can be added in AUR or wherever people use python 3.13 early. If I see no movement to fix the issue in GObject I’ll merge this in main.

[carlosal1015]

Thanks, just in time for my talk today 😄

It is working and was patched in AUR.

[Cimbali]

Great! Let's keep this open for now to not forget about it though.