It appears the following one-liner patch fixes the permissions problem in Lubuntu, which is caused by /usr/share/ubiquity/plugininstall.py being called without elevated privileges.
=== modified file 'ubiquity/filteredcommand.py' --- ubiquity/filteredcommand.py 2013-02-19 11:33:07 +0000 +++ ubiquity/filteredcommand.py 2018-04-05 22:14:08 +0000 @@ -193,6 +193,8 @@ # default action or else they won't notice if the # debconffilter dies. signal.signal(signal.SIGPIPE, signal.SIG_DFL) + # Regain root. + misc.regain_privileges() ret = subprocess.call(self.command, preexec_fn=subprocess_setup) if ret != 0: It is not clear to me if this is correct, or why plugininstall.py is handled via this code path on Lubuntu when it evidently is not on other flavors (or alternatively: why this code is called with privileges already raised on all other flavors). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1754174 Title: [Lubuntu] "Install Lubuntu" fails with several commands not found and permission denied To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1754174/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs