Local install roundup

2010-02-27

There are going to be times when you need to stray outside your packaging system to get a version of a module. It might be that the version your vendor ships is too old, or that it’s not packaged. One way around is to set up a local library path tucked away in your home directory, and install modules there.

While there’s a bigger topic on the ways that this can mess you up, here’s a cleaned up page out of my notebook on how to set this up for various languages.

Python

virtualenv creates what feels a little like a chroot which you can install your libraries into. Getting it going is very simple:

$ virtualenv .virtualenv
New python executable in .virtualenv/bin/python
Installing setuptools............done.

and the add that to the start of your $PATH by adding something like this to your .bashrc

export PATH="$HOME/.virtualenv/bin:$PATH"

And you’re good to go. Installing modules is then as simple as:

$ easy_install Pygments
Searching for Pygments
Reading http://pypi.python.org/simple/Pygments/
Reading http://pygments.org/
Reading http://pygments.pocoo.org/
Best match: Pygments 1.2.2
Downloading http://pypi.python.org/packages/2.5/P/Pygments/Pygments-1.2.2-py2.5.egg#md5=bbb12b2aba148e69923c7143d2af73bd
Processing Pygments-1.2.2-py2.5.egg
creating /home/richardc/.virtualenv/lib/python2.5/site-packages/Pygments-1.2.2-py2.5.egg
Extracting Pygments-1.2.2-py2.5.egg to /home/richardc/.virtualenv/lib/python2.5/site-packages
Adding Pygments 1.2.2 to easy-install.pth file
Installing pygmentize script to /home/richardc/.virtualenv/bin

Installed /home/richardc/.virtualenv/lib/python2.5/site-packages/Pygments-1.2.2-py2.5.egg
Processing dependencies for Pygments
Finished processing dependencies for Pygments

Ruby

gem respects a $GEM_HOME environment variable, or will default to populating a $HOME/.gem directory tree if you’re not running as root.

To make your gem-installed binaries come first, we’re back to adding things to our .bashrc

export GEM_HOME="$HOME/.gem"
export PATH="$GEM_HOME/ruby/1.8/bin:$PATH"

then you can just use gem like normal:

$ gem install rake
Successfully installed rake-0.8.7
1 gem installed
Installing ri documentation for rake-0.8.7...
Installing RDoc documentation for rake-0.8.7...

and hey presto, rake.

$ rake --version
rake, version 0.8.7

Perl

Perl’s local::lib sets up all the necessary environment to install CPAN modules into local paths, so again to our .bashrc

eval $( perl -Mlocal::lib=$HOME/.perl-local )

And then you can just install things using the CPAN shell as normal.

$ cpan -i Tie::File
[...]
Installing /home/richardc/.perl-local/lib/perl5/Tie/File.pm
Installing /home/richardc/.perl-local/man/man3/Tie::File.3
Writing /home/richardc/.perl-local/lib/perl5/i686-linux/auto/Tie/File/.packlist
Appending installation info to /home/richardc/.perl-local/lib/perl5/i686-linux/perllocal.pod
  MJD/Tie-File-0.96.tar.gz
  /usr/bin/make install  -- OK