As per https://perlmaven.com/cant-locate-inc-module-install-in-inc, the inc/
directory should not be under version control.
fixes #2914
$ sudo apt-get install cpanminus
$ sudo cpanm .
$ cd ~/i3/AnyEvent-I3
+$ sudo cpanm Module::Install
$ sudo cpanm .
--------------------------------------------------------------------------------
$ cd ~/i3/testcases
$ sudo cpan .
$ cd ~/i3/AnyEvent-I3
+$ sudo cpan Module::Install
$ sudo cpan .
--------------------------------------------------------------------------------