Today I discovered that I was using Perl 5, version 14.2 (v5.14.2) from the Ubuntu 12.04 packages. It includes 57 registered patches. As it is a 2011 version, I’ve decided to switch from the Ubuntu packages to a more recent one (and considered as stable by the Perl community although it is not by the Debian one).

As I love to use local::lib and cpanm, I’ve chosen to use Perlbrew to achieve the installation of this last stable version. The tool seems as convenient as cpanm and local::lib, it is known for making your life easier when dealing with Perl installations.

Perlbrew is :

• a tool to install different versions of perls and switch through them
• an admin-free installation management system, means, as for local::lib, you don’t even need to have superuser rights to use it, so you don’t have to suck the admin’s ass
• it’s just like RVM for those who know Ruby

The reason I write this post is that I encountered a tiny problem when installing Perlbrew on an Ubuntu box, so I hope it could be useful for you.

I assume that you already have cpanm and local::lib installed (you don’t use the root account nor sudo).

1

$ cpanm perlbrew

1
2
3
4
5
6
7
8
9
10
11
12

$ perlbrew init

perlbrew root (~/perl5/perlbrew) is initialized.
  
Append the following piece of code to the end of your ~/.bash_profile and
start a new shell, perlbrew should be up and fully functional from there:
  
    source ~/perl5/perlbrew/etc/bashrc
      
Simply run `perlbrew` for usage details.
      
Happy brewing!

`

It has created some files in ~/.perlbrew. You need to add the one that fit your environment in your configuration file (.bashrc or other) :

1

source ~/perl5/perlbrew/etc/bashrc

Now start a new shell or source your shell configuration file, that’s it Perlbrew is on! You can check which Perls are available :

1
2
3
4
5
6
7
8
9
10
11
12

$ perlbrew available
  perl-5.19.10
  perl-5.18.2
  perl-5.16.3
  perl-5.14.4
  perl-5.12.5
  perl-5.10.1
  perl-5.8.9
  perl-5.6.2
  perl5.005_04
  perl5.004_05
  perl5.003_07

So pick a version, or ask for the last stable one. In fact, that’s the moment I encountered an issue with Perlbrew and Devel::PatchPerl.pm. I asked for last stable Perl’s installation but it failed :

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

$ perlbrew install stable
Installing /home/smonff/perl5/perlbrew/build/perl-5.18.2 into
~/perl5/perlbrew/perls/perl-5.18.2
  
This could take a while. You can run the following command on
another shell to track the status:
  
  tail -f ~/perl5/perlbrew/build.perl-5.18.2.log
  
Installation process failed. To spot any issues, check
  
    /home/smonff/perl5/perlbrew/build.perl-5.18.2.log
      
You might also want to try upgrading patchperl before trying again:
      
  perlbrew install-patchperl

As the process was failing, I tailed the logs :

1
2
3
4
5
6
7

$ tail -f ~/perl5/perlbrew/build.perl-5.18.2.log
Can't locate Devel/PatchPerl.pm in @INC (@INC contains: /etc/perl
/usr/local/lib/perl/5.14.2 /usr/local/share/perl/5.14.2
/usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.14
/usr/share/perl/5.14 /usr/local/lib/site_perl .) at
/home/smonff/perl5/bin/patchperl line 12.
BEGIN failed--compilation aborted at /home/smonff/perl5/bin/patchperl line 12.

I tried to update a Devel::PatchPerl, but updating stupidely without understanding or without reading the doc is useless. Finally, I found the answer on StackOverflow, even if it was clearly mentioned in the Perlbrew logs, you should better read sentences till the end and do what you’re told. Perlbrew seems to embark its own Devel::PatchPerl in ~/perl5/perlbrew/bin, and you should not use the core one. More about this on Perlbrew website… So now do what you’re told :

1

$ perlbrew install-patchperl

Ok, it seems everything is ok. I tried some perl -v and the version has changed. But when installing Dancer with cpanm and setup a test Dancer application, Dancer was reconizing the old version :

That’s because, in the same spirit when need a dedicated patchperl, the cpanm installation need a special process too :

1
2
3
4
5

$ perlbrew install-cpanm
  
cpanm is installed to
  
  /home/smonff/perl5/perlbrew/bin/cpanm

This fixes the issues, the environment is ready. I believe all previously installed modules through cpanm should be re-installed now.

Perls installations will be very very easy to achieve :

1
2

$ perlbrew install stable
perl-5.18.2 is successfully installed.

Happy brewing !

References

• perlbrew.pl/
• Perlbrew on MetaCPAN
• A talk about Perlbrew by Kang-min Liu