My example of building an appimage is stop working

[anki-code]

Hi @niess !

Could you please take a look into this case:

cd /tmp 
# this is my test example that was working before
git clone https://github.com/anki-code/appimage-test
mv appimage-test rvr
cd rvr
python -m python_appimage build app --python-version 3.8 appimage

And I've got:

python -m python_appimage build app --python-version 3.8 appimage
[2021-04-30 20:22:17,349] EXTRACT  python3.8.9-cp38-cp38-manylinux1_x86_64.AppImage
[2021-04-30 20:22:19,682] BUNDLE   xonsh.desktop
[2021-04-30 20:22:19,683] BUNDLE   xonsh.appdata.xml
[2021-04-30 20:22:22,572] BUNDLE   /tmp/rvr
Traceback (most recent call last):
  File "/opt/miniconda3/lib/python3.8/runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/opt/miniconda3/lib/python3.8/runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "/opt/miniconda3/lib/python3.8/site-packages/python_appimage/__main__.py", line 109, in <module>
    main()
  File "/opt/miniconda3/lib/python3.8/site-packages/python_appimage/__main__.py", line 105, in main
    command.execute(*command._unpack_args(args))
  File "/opt/miniconda3/lib/python3.8/site-packages/python_appimage/commands/build/app.py", line 240, in execute
    system(('./AppDir/AppRun', '-m', 'pip', 'install', '-U',
  File "/opt/miniconda3/lib/python3.8/site-packages/python_appimage/utils/system.py", line 42, in system
    raise RuntimeError(err)
RuntimeError: WARNING: Value for scheme.headers does not match. Please report this to <https://github.com/pypa/pip/issues/9617>
distutils: /tmp/python-appimage-iw219et5/AppDir/opt/python3.8/include/python3.8/UNKNOWN
sysconfig: /tmp/python-appimage-iw219et5/AppDir/opt/python3.8/include/python3.8
WARNING: Additional context:
user = False
home = None
root = None
prefix = None
  DEPRECATION: A future pip version will change local packages to be built in-place without first copying to a temporary directory. We recommend you use --use-feature=in-tree-build to test your packages with this new behavior before it becomes the default.
   pip 21.3 will remove support for this functionality. You can find discussion regarding this at https://github.com/pypa/pip/issues/7555.
WARNING: Value for scheme.headers does not match. Please report this to <https://github.com/pypa/pip/issues/9617>
distutils: /tmp/python-appimage-iw219et5/AppDir/opt/python3.8/include/python3.8/UNKNOWN
sysconfig: /tmp/python-appimage-iw219et5/AppDir/opt/python3.8/include/python3.8
WARNING: Additional context:
user = False
home = None
root = None
prefix = None

Could you please give an advice what I'm doing wrong or probably this is an upstream issue? Because this example was working before.

If this issue appeared after the updating the Python appimages may be we should start doing the releases instead of continuous release? You can use latest keyword to download the image from the latest release i.e.:

https://github.com/xonsh/xonsh/releases/latest/download/xonsh-x86_64.AppImage

Thanks!