Symbol lookup error for my ~/perl5/lib/perl5

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

Hello. I am getting a symbol lookup error when trying to install a module to ~/perl5/lib or use that lib in apache2.

When trying to install a module with cpan I get the following:

/usr/bin/perl: symbol lookup error: /home/me/perl5/lib/perl5/x86_64-li
+nux-gnu-thread-multi/auto/List/Util/Util.so: undefined symbol: Perl_x
+s_apiversion_bootcheck
[download]

When I used that directory in apache2, I get the following error in my error log:

/usr/bin/perl: symbol lookup error: /home/me/perl5/lib/perl5/x86_64-li
+nux-gnu-thread-multi/auto/List/Util/Util.so: undefined symbol: Perl_x
+s_apiversion_bootcheck
[download]

I don't know if it is just List::Util that has a problem or my entire ~/perl5/lib.

This issue happened after I upgraded my Debian distribution from 8 (Jessie) to 9 (Stretch). perl -v returns the following:

This is perl 5, version 24, subversion 1 (v5.24.1) built for x86_64-li
+nux-gnu-thread-multi
[download]

which perl returns:

/usr/bin/perl
[download]

I can not think of anything else I need to add that will help with figuring out this problem.

All help is appreciated!

This issue appears to be resolved. The suggestion of an Anonymous Monk to rename the dir and reinstall the modules seems to have worked. Thank you all for your patience.

No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!

Lady Aleena

Comment on Symbol lookup error for my ~/perl5/lib/perl5 Select or Download Code

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Re: Symbol lookup error for my ~/perl5/lib/perl5 by bliako (Monsignor) on Jun 06, 2019 at 00:02 UTC
karlgoethebier is right in the sense that you may not have now two Perls but over time you did have two or more Perls via the upgrades. The error message tells me that List::Util has not been recompiled and linked with the new Perl after the Perl exe upgrade. When an upgrade happens, then all modules which have XS/C components must be re-compiled and re-linked to the new Perl. But often the list of said modules is incomplete (perhaps because we usually do not upgrade via the system's package manager but Perl's package manager). So (re)installing List::Util (and all Perl modules) via the system's package manager will most likely fix the problem (). Be warned that forcing a Perl upgrade may break some things in your system because GNU/Linux uses Perl for housekeeping and certain versions need certain Perl versions etc. The solution is perlbrew. It will allow you to have as many Perls as you wish without tampering with system's Perl at all. Edit* thanks marto: ) If you can't use the system's package manager* then you can use cpan-outdated to list all outdated modules and possibly pipe its output to `cpanm` for reinstalling. For example: `cpan-outdated \| cpanm -L ~/perl5 --reinstall`. Edit2 anonymous monk below (Re: Symbol lookup error for my ~/perl5/lib/perl5) makes a valid point that `cpanm` may not work because of this incompatibility and suggests a workaround	[reply] [d/l] [select]
Re^2: Symbol lookup error for my ~/perl5/lib/perl5 by marto (Cardinal) on Jun 06, 2019 at 12:40 UTC
"So (re)installing List::Util (and all Perl modules) via the system's package manager will most likely fix the problem." Many people install to a local directory (also local::lib) do so because they specifically can't (or don't want to) alter the system perl.	[reply]
Re: Symbol lookup error for my ~/perl5/lib/perl5 by karlgoethebier (Abbot) on Jun 05, 2019 at 20:07 UTC
Let me guess: Do you have two versions of Perl installed on your box? Regards, Karl ŤThe Crux of the Biscuit is the Apostropheť `perl -MCrypt::CBC -E 'say Crypt::CBC->new(-key=>'kgb',-cipher=>"Blowfish")->decrypt_hex($ENV{KARL});'`Help	[reply] [d/l]
Re^2: Symbol lookup error for my ~/perl5/lib/perl5 by Lady_Aleena (Priest) on Jun 05, 2019 at 21:34 UTC
Not that I am aware of. *No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!* Lady Aleena	[reply]
Re: Symbol lookup error for my ~/perl5/lib/perl5 by Anonymous Monk on Jun 06, 2019 at 14:19 UTC
TL;DR: `mv ~/perl5 ~/perl5.bak` should restore scripts such as `cpan` that depend on `List::Util` but get the version compiled for older version of Perl from `~/perl5`. This has happened because Debian Jessie has Perl v5.20, Debian Stretch has v5.24, both Perls expect their modules to be in `~/perl5` (probably via `local::lib`) but are binary incompatible. It is likely that you have the compatible version of `List::Util` (and other `cpan` dependencies) installed somewhere in `/usr`, but modules installed via `local::lib` take precedence and manage to crash the interpreter before it can use right one. One your Perl installation works, you can visit `~/perl5.bak` to see which modules you would need to install again, for the new version of Perl.	[reply] [d/l] [select]
Re^2: Symbol lookup error for my ~/perl5/lib/perl5 by Lady_Aleena (Priest) on Jun 06, 2019 at 16:37 UTC
Will `cpan` rebuild `~/perl5` when I go to reinstall the modules or do I need to recreate some of the directory structure? *No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!* Lady Aleena	[reply] [d/l] [select]
Re^3: Symbol lookup error for my ~/perl5/lib/perl5 by karlgoethebier (Abbot) on Jun 07, 2019 at 11:43 UTC
Splendid advice was already given by some fellow monks. Just a little addendum: For the future i would recommend that you make it so. Didnt I mention this already 😎 ? Best regards, Karl ŤThe Crux of the Biscuit is the Apostropheť `perl -MCrypt::CBC -E 'say Crypt::CBC->new(-key=>'kgb',-cipher=>"Blowfish")->decrypt_hex($ENV{KARL});'`Help	[reply] [d/l]
Re^3: Symbol lookup error for my ~/perl5/lib/perl5 by Anonymous Monk on Jun 06, 2019 at 20:22 UTC
I think that `cpan` should be able to rebuild everything by itself. At most, `mkdir ~/perl5` might be needed but probably isn't.	[reply] [d/l] [select]


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