"cpan -l" as 'root' on initial run breaking non-root Perl users if 'root' umask restrictive to 'root'

[MrPippin66]

On a system with the Perl CPAN module installed, but has never been used, if you run "cpan -l", the initial discovery will cause 'perl5' to be created in all @inc location (if missing) with the umask setting of 'root'. If this is set restrictively (077 for instance), this will break the normal behavior for all non-root Perl users, which will have no read access to those 'perl5' directories.

Perl = 5.26.3-422
Perl CPAN = 2.18-399

[michal-josef-spacek]

This is not true as I understand.

(upstream cpan)
When I run cpan -l for the first time, cpan needs to be configured and the results depend on the answers from the user.
There are some options on how to configure. Probably no one could create a problematic situation with umask. When the user installs some Perl module by cpan, umask will create issues with paths.

(Fedora cpan)
There is a patch (https://src.fedoraproject.org/rpms/perl-CPAN/blob/rawhide/f/CPAN-2.18-Attemp-to-create-site-library-directories-on-first-t.patch) which is changing behavior and cpan, in this case, is creating main paths more automatically.
The "issue" with umask is moving more visible than in installing of Perl modules.

Some results from me:

• Usage of umask with 0077 setting in case of installing Perl modules to /usr/local/ isn't the right approach.
• Configuration of cpan in case of cpan -l is questionable. See "cpan -l" run without configuration #194
• I am proposing to improve documentation about configuration in the case of usage in some commands.

[MrPippin66]

Thanks for the response, and upon viewing the Fedora code vs the CPAN module here, I can see this DOES appear to be Fedora/Red Hat specific with them creating these directories without doing a bit more validation.

[jplesnik]

In Fedora cpan, the creating of site repositories could be fixed by adding option chmod => 0755 which is not modified by current umask.

[Tronde]

In Fedora cpan, the creating of site repositories could be fixed by adding option chmod => 0755 which is not modified by current umask.

Making sure to create the directories in a user's @INC with a file mode of 0755 would definitely improve things and prevent an impact on the non-root Perl users of a system.

Still as a system administrator or user I don't expect that a command that is supposed to list something (e.g. cpan -l) is actually changing something under certain circumstances. Linking #194 here which would be the best solution to improve the behavior for the cpan -l command.

[briandfoy]

I've fixed the issue with #194 in my forked version of cpan in briandfoy/app-cpan-upgraded#1. I'd fix the issue here but this repo is unmaintained. See #187.