cpan problems when /tmp and /var are existing symbolic links

PhilipS has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to install modules from cpan on a machine where /tmp is an existing symbolic link. So Archive::Zip fails with "Could not extract xxx safely: /tmp is an existing symbolic link."

(I get the same issue with /var if I try to make/test/install manually. And I don't have permissions to change the symbolic links on that machine.)

Is there a workaround? I don't see any easy way to tell cpan to use a different directory as a temporary directory.

Thanks,
Philip

Comment on cpan problems when /tmp and /var are existing symbolic links

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Re: cpan problems when /tmp and /var are existing symbolic links by davido (Cardinal) on Jan 23, 2019 at 08:39 UTC
I believe the tests for Archive::Zip utilize File::Temp, which discovers the tempdir using File::Spec. File::Spec suggests you can hint an alternate tempdir by setting the TMPDIR environment variable. Proof of concept: In your homedir create a directory named `~/tmp` Execute `TMPDIR=~/tmp perl -MFile::Spec::Functions=tmpdir -E 'say tmpdir()'` You will see your alternate tempdir returned. This is what Archive::Zip should actually use. So you could possibly do this: `TMPDIR=~/tmp cpanm Archive::Zip` [download] And if that doesn't work, built it yourself by downloading the archive from CPAN, extracting it to a directory, then: `perl Makefile.PL make TMPDIR=~/tmp make test make install` [download] ...or just `cpanm -f`, but those tests for linkdir do exist for a reason. ;) Dave	[reply] [d/l] [select]
Re: cpan problems when /tmp and /var are existing symbolic links by Corion (Patriarch) on Jan 23, 2019 at 09:35 UTC
CPAN uses Archive::Zip which uses File::Temp. There, `$ENV{TMPDIR}` is suggested to set up a writable temp directory. Maybe this works on your system.	[reply] [d/l]
Re: cpan problems when /tmp and /var are existing symbolic links by afoken (Chancellor) on Jan 23, 2019 at 08:25 UTC
Can you show the output of `o conf` entered into the cpan prompt? I don't think cpan should even try to extract files to /tmp, unless it was configured to do so. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply] [d/l]
Re^2: cpan problems when /tmp and /var are existing symbolic links by davido (Cardinal) on Jan 23, 2019 at 08:40 UTC
I watched `/tmp` on my computer while doing the `make`, `make test` dance and saw that it's the tests that tinker around inside `/tmp`. Skimming through the scripts in `t/` confirmed this. Dave	[reply] [d/l] [select]