[Bug 1903027] [NEW] Regression: Unable to run PyGObject using a Virtual Environment after updating to 20.10

[Roberto Leinardi]

Public bug reported:

After updating from Ubuntu 20.04 to Ubuntu 20.10 I am not able to run
PyGObject applications on a Python Virtual Environment.

I can reproduce the issue following these simple steps:

sudo apt-get install python3-venv
python3 -m venv venv
source env/bin/activate
pip install PyGObject==3.38.0
python3 hw.py

Where hw.py is the standard PyGObject Hello World:


#!/usr/bin/env python3

import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk

window = Gtk.Window(title="Hello World")
window.show()
window.connect("destroy", Gtk.main_quit)
Gtk.main()


When I try to run it, it throws this error:

$ python3 hw.py 
Traceback (most recent call last):
  File "hw.py", line 3, in <module>
    import gi
  File "/home/leinardi/temp/hw/venv/lib/python3.8/site-packages/gi/__init__.py", line 40, in <module>
    from . import _gi
ImportError: libffi.so.7: cannot open shared object file: No such file or directory


Running hw.py on the System Environment of 20.10 works correctly (the issue only happens when using the Virtual Environment).

A workaround is to find and provide a copy of libffi.so.7 in
/usr/lib/x86_64-linux-gnu/ but, since this library version is not
available inside the official repositories of Ubuntu 20.10, this is a
difficult and unsafe operation.

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: python3-venv 3.8.6-0ubuntu1
ProcVersionSignature: Ubuntu 5.8.0-26.27-generic 5.8.14
Uname: Linux 5.8.0-26-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu50
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Thu Nov  5 10:57:41 2020
InstallationDate: Installed on 2019-09-27 (404 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Alpha amd64 (20190923)
SourcePackage: python3-defaults
UpgradeStatus: Upgraded to groovy on 2020-11-04 (0 days ago)

** Affects: python3-defaults (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug groovy

** Attachment added: "hw.py"
   https://bugs.launchpad.net/bugs/1903027/+attachment/5431506/+files/hw.py

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https://bugs.launchpad.net/bugs/1903027

Title:
  Regression: Unable to run PyGObject using a Virtual Environment after
  updating to 20.10

Status in python3-defaults package in Ubuntu:
  New

Bug description:
  After updating from Ubuntu 20.04 to Ubuntu 20.10 I am not able to run
  PyGObject applications on a Python Virtual Environment.

  I can reproduce the issue following these simple steps:

  sudo apt-get install python3-venv
  python3 -m venv venv
  source env/bin/activate
  pip install PyGObject==3.38.0
  python3 hw.py

  Where hw.py is the standard PyGObject Hello World:

  
  #!/usr/bin/env python3

  import gi
  gi.require_version("Gtk", "3.0")
  from gi.repository import Gtk

  window = Gtk.Window(title="Hello World")
  window.show()
  window.connect("destroy", Gtk.main_quit)
  Gtk.main()

  
  When I try to run it, it throws this error:

  $ python3 hw.py 
  Traceback (most recent call last):
    File "hw.py", line 3, in <module>
      import gi
    File "/home/leinardi/temp/hw/venv/lib/python3.8/site-packages/gi/__init__.py", line 40, in <module>
      from . import _gi
  ImportError: libffi.so.7: cannot open shared object file: No such file or directory

  
  Running hw.py on the System Environment of 20.10 works correctly (the issue only happens when using the Virtual Environment).

  A workaround is to find and provide a copy of libffi.so.7 in
  /usr/lib/x86_64-linux-gnu/ but, since this library version is not
  available inside the official repositories of Ubuntu 20.10, this is a
  difficult and unsafe operation.

  ProblemType: Bug
  DistroRelease: Ubuntu 20.10
  Package: python3-venv 3.8.6-0ubuntu1
  ProcVersionSignature: Ubuntu 5.8.0-26.27-generic 5.8.14
  Uname: Linux 5.8.0-26-generic x86_64
  NonfreeKernelModules: nvidia_modeset nvidia
  ApportVersion: 2.20.11-0ubuntu50
  Architecture: amd64
  CasperMD5CheckResult: skip
  CurrentDesktop: ubuntu:GNOME
  Date: Thu Nov  5 10:57:41 2020
  InstallationDate: Installed on 2019-09-27 (404 days ago)
  InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Alpha amd64 (20190923)
  SourcePackage: python3-defaults
  UpgradeStatus: Upgraded to groovy on 2020-11-04 (0 days ago)

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