Re: What is cpan (the installer) doing prepending all these directories to the PERL5LIB path?

[ikegami]

but they seem to be hanging around long after they are necessary.

That's impossible. A program can't change the environment of another process. It can change its own, and it can set the starting environment of its children. That's it. That means that the cpan process can't modify your shell's environment.

If you're trying to explain env var found in your shell, start by checking your shell's login and startup scripts (e.g. .profile, .bash_profile, .bashrc).

[ysth]

He's not saying anything like that. When he's doing an install it is letting him know it is adding other builds to PERL5LIB for that install, and the number is increasing, not that that env var is somehow persisting.

[Intrepid]

That's right, ysth. I do understand how env works for the currently-running process, its child processes, its parent process, and so on, ikegami.

Unrelated to the reported behavior is a spurious error message I'm seeing:

prerequisite moduleFile::Basename not known

This message also started appearing rather recently and doesn't seem to be connected to any actual failure in cpan. I thought I'd mention it here since it's a "while we're discussing cpan" kind of thing.

    — Soren


Nov 14, 2025 at 19:44 UTC

[ikegami]

So what do you claim is sticking around?