Travis CI Install perl module with non-perl language

Question

How do you install perl modules on linux and mac platforms on Travis CI when the language is not set to perl? I'm compiling a C program with perl test scripts.

If the language is perl, cpanm is available:

cpanm JSON

Otherwise if the platform is linux:

sudo apt-get install libjson-pp-perl

But when on mac cpanm and apt-get are not available. The mac platform has the brew command available to install programs but I can't figure out if I need to install a fresh version of perl instead of just a module for the system perl version.

The mac version also has the cpan JSON command available, but it hangs to go through an interactive first-run configuration.

Answer 1

Thanks to @simbabque's comment I installed cpanm to the system perl, then used cpanm to install the perl module and it works:

curl -L https://cpanmin.us | sudo perl - --sudo App::cpanminus
sudo cpanm JSON

I've not yet figured out the easiest way to install locally without using sudo.

Edit: Without requiring sudo, using local::lib to setup $PERL5LIB paths etc.:

# Install modules into ~/perl5 using system perl
curl -L https://cpanmin.us | perl - App::cpanminus
~/perl5/bin/cpanm local::lib
~/perl5/bin/cpanm JSON

# Add path to ~/perl5 modules to ~/.bashrc
echo '[ $SHLVL -eq 1 ] && eval "$(perl -I$HOME/perl5/lib/perl5 -Mlocal::lib)"' >> ~/.bashrc