Perl - How to reference a module installed locally? - perl

Question

I have a module Term:TermKey, which is in a file TermKey.pm. I don't want to install it into my perl; I want it to be referenced locally so that the script can be moved to other machines without messing about with each perl installation. How do I do this? None of the recommendations I have seen online works. I always get some form of:
Can't locate loadable object for module Term::TermKey in #INC (#INC contains: /home/fritz/multi.kodis/Term /etc/perl /usr/local/lib/perl/5.18.2 /usr/local/share/perl/5.18.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.18 /usr/share/perl/5.18 /usr/local/lib/site_perl .) at test.pl line 6.
Compilation failed in require at test.pl line 6.
BEGIN failed--compilation aborted at test.pl line 6.
To test this. I placed copies of TermKey.pm in all of:
./TermKey.pm
./Term/TermKey.pm
./Term/Term/TermKey.pm
(just as a test)
Yet it doesn't work for any of:
use lib '';
use Term::TermKey;
use lib '.';
use Term::TermKey;
use lib './';
use Term::TermKey;
use lib './Term';
use Term::TermKey;
use lib './Term/';
use Term::TermKey;
use lib '/home/[user]/[project]'
use Term::TermKey;
use lib '/home/[user]/[project]/Term'
use Term::TermKey;
use FindBin;
use lib "$FindBin::RealBin";
use Term::TermKey;
What the heck? This should be easy, what am I missing?

Answer 1

"Can't locate loadable object for module" does not mean that Perl can't find Term/TermKey.pm. It means that it can't find Term/TermKey.so (or whatever shared libraries are called on your platform).
Term::TermKey is not a pure-Perl module. Instead, it includes XS code, which needs to be compiled into C and then into a shared library. Also, that library links to libtermkey, which must also be installed on your system.
This makes it much harder to move the module from system to system. An XS module compiled for Perl 5.18.2 won't work with 5.20.0; it has to be recompiled. You can upgrade minor releases (like from 5.18.0 to 5.18.2) without having to recompile, although going the other direction (from 5.18.2 to 5.18.0) isn't guaranteed to work.
So, you might be able to get this to work if all the machines are running the same version of Perl on the same OS with the same libraries installed. The easiest way (if it works at all) would be to install cpanm and local::lib and do something like:
cpanm --local-lib some-dir Term::TermKey
Then you could copy some-dir to another machine (with the caveats listed above). It isn't necessary to install local::lib on the other machines; you can just
use lib 'some-dir/lib/perl5';