Cannot install getmail 5.16

Greetings. I am trying to come back to getmail, after many years of absence. I managed to install 5.16 and run it flawlessly on Xubuntu 22.04, using the Python2.7 package that is available from this distribution.

In contrast, the installation aborted on another computer that runs Xubuntu 24.04, which does not support Python2 anymore. I downloaded the AppImage recommended by Mr. Cazabon and installed it according to his instructions. I then tried to install getmail, but apparently a permission issue arose during the installation process. Here are the results:

The building process runs fine:

$ python2 setup.py build
running build
running build_py
creating build
creating build/lib
creating build/lib/getmailcore
copying getmailcore/imap_utf7.py -> build/lib/getmailcore
copying getmailcore/utilities.py -> build/lib/getmailcore
copying getmailcore/logging.py -> build/lib/getmailcore
copying getmailcore/_retrieverbases.py -> build/lib/getmailcore
copying getmailcore/retrievers.py -> build/lib/getmailcore
copying getmailcore/compatibility.py -> build/lib/getmailcore
copying getmailcore/message.py -> build/lib/getmailcore
copying getmailcore/baseclasses.py -> build/lib/getmailcore
copying getmailcore/constants.py -> build/lib/getmailcore
copying getmailcore/_pop3ssl.py -> build/lib/getmailcore
copying getmailcore/destinations.py -> build/lib/getmailcore
copying getmailcore/exceptions.py -> build/lib/getmailcore
copying getmailcore/filters.py -> build/lib/getmailcore
copying getmailcore/__init__.py -> build/lib/getmailcore
running build_scripts
creating build/scripts-2.7
copying and adjusting getmail -> build/scripts-2.7
copying and adjusting getmail_fetch -> build/scripts-2.7
copying and adjusting getmail_maildir -> build/scripts-2.7
copying and adjusting getmail_mbox -> build/scripts-2.7
copying and adjusting getmail-gmail-xoauth-tokens -> build/scripts-2.7
changing mode of build/scripts-2.7/getmail from 664 to 775
changing mode of build/scripts-2.7/getmail_fetch from 664 to 775
changing mode of build/scripts-2.7/getmail_maildir from 664 to 775
changing mode of build/scripts-2.7/getmail_mbox from 664 to 775
changing mode of build/scripts-2.7/getmail-gmail-xoauth-tokens from 664 to 775

So far so good, but then the installation (as root) aborts:

# python2 setup.py install
running install
running build
running build_py
running build_scripts
running install_lib
creating /tmp/.mount_pythonsHwdw8/usr/python/lib/python2.7/site-packages/getmailcore
error: could not create '/tmp/.mount_pythonsHwdw8/usr/python/lib/python2.7/site-packages/getmailcore': Read-only file system

Now my /tmp directory is 41777 (octal mode), meaning anybody can read, write and execute, but cannot tamper with someone else's files (sticky bit). I understand these are the standard permissions for /tmp.

Exactly the same error occurred when I used another AppImage, this time from github.

Am I overlooking something? Any help will be appreciated.

Sincerely,
Francisco