Foreign packages in GNU Guix
Examples from Ruby gems, Python modules and
R/CRAN
Pjotr Prins & David Thompson
FOSDEM
January 30th, 2016
UMC Utrecht/UTHSC GeneNetwork.org

Foreign packages in GNU Guix – p. 1

GNU Guix
What is it to me?

Foreign packages in GNU Guix – p. 2

Holy grail
Controlled software deployment
Control the full dependency graph
Write once and reproduce any time
Understand what is happening

Foreign packages in GNU Guix – p. 3

Foreign packages
What are they?

Foreign packages in GNU Guix – p. 4

Foreign packages?
Non-native guix packages: Perl, Python, Ruby, R
but also emacs, Firefox, etc.
I.e., any tool that wants to install software locally

Foreign packages in GNU Guix – p. 5

Ruby gems
Unpacks gem in global Ruby directory
Or in $GEM_HOME
gem major number versioning
gems are not isolated, not even between ruby versions
rvm, rbenv, bundler try to solve the mess
I got to dislike rvm and bundler with a passion

Foreign packages in GNU Guix – p. 6

Solving the mess
if $GEM_HOME is isolated the gem tool can do the job
/gnu/store/p8ks1l9cl-ruby-2.2.4/bin/ruby -v
ruby 2.2.4p230 (2015-12-16 revision 53155) [x86_64-linux]

export GEM_HOME=˜/.gem/p8ks1l9cl-ruby-2.2.4/2.2.0
export GEM_PATH=˜/.gem/p8ks1l9cl-ruby-2.2.4/2.2.0
gem install log4r
ruby -e require ’log4r’

Foreign packages in GNU Guix – p. 7

It works!
At this point I am living with a
reproducible modern ruby
no need for rvm, rbenv or bundler
gem works. Gems are isolated but not fully
reproducible
bundler still works
Great for me

Foreign packages in GNU Guix – p. 8

But. . .
I am still not satisfied

Foreign packages in GNU Guix – p. 9

For real
System-wide deployments
Reproducible: when and where should not matter
I.e., we want full control over the depency graph
So, Ruby gems ultimately need to go into GNU Guix
With help from David I started adding ruby gem
support

Foreign packages in GNU Guix – p. 10

Guix gem support
A short code walk
guix/build-system/ruby.scm

- defines what a package

should be like
guix/build/ruby-build-system.scm

- unpacks and builds the

package
guix/import/ruby.scm

- automatically imports gems

gnu/package/ruby.scm

- contains Ruby and gems

Foreign packages in GNU Guix – p. 11

Import gem
guix import gem log4r
(package
(name "ruby-log4r")
(version "1.1.10")
(source
(origin
(method url-fetch)
(uri (rubygems-uri "log4r" version))
(sha256
(base32
"0ri90q0frfmigkirqv5ihyrj59xm8pq5zcmf156cbdv4r4l2jicv"))))
(build-system ruby-build-system)
(synopsis
"See also: http://logging.apache.org/log4j")
blah, blah)

Foreign packages in GNU Guix – p. 12

Install gem
guix package -i ruby-log4r

Installs /gnu/store/409cynfy62-ruby-log4r-1.1.10/lib/
Symlinks ˜/.guix-profile/lib/ruby/gems/2.2.0/gems/
guix package - -search-paths

export GEM_PATH=˜/.guix-profile/lib/ruby/gems/2.2.0
ruby -e require ’log4r’

Foreign packages in GNU Guix – p. 13

Done
We have
A fully reproducible ruby
A fully reproducible gem
Write once and deploy anywhere

Foreign packages in GNU Guix – p. 14

Python modules
The GNU Guix python build-system
guix package -A python
guix package -i python2-parsedatetime

Imports from pypi
Installs anything with a setup.py
Supports python3 and python2 with one definition:
(define-public python2-parsedatetime
(package-with-python2 python-parsedatetime))

Foreign packages in GNU Guix – p. 15

R modules
The GNU Guix R build-system
Imports from CRAN
Installs anything on CRAN and bioconductor
R modules are not tied to R releases!

Foreign packages in GNU Guix – p. 16

What is Guix to me?
Dependable software deployment
Reproducible software deployment
Incremental software development
1. As a system administrator (users, versions,
transactions)
2. As a software developer (user support, multiple
versions)

Foreign packages in GNU Guix – p. 17

Debian etc.
How does GNU Guix compare to other popular
distributions?
Versioning is NOT a problem
Multiple targets are NOT a problem (+/- ssl, BLAS/Atlas)
Foreign imports are easy
Packaging is relatively easy
The only dependency is the Linux kernel API

Foreign packages in GNU Guix – p. 18

Docker?
With Docker order and time of software installation
matter
The build is not reproducible
Sending multiple GBs around for a simple thing?
File systems and network policies? At what level
should we care?
You must be MAD to use Docker when there is GNU
Guix

Foreign packages in GNU Guix – p. 19

Conclusion
Adding packages is easy
Guix is hackable - with a bit of LISP adding features
such as foreign package support is surprisingly easy
GNU Guix has the right level of abstraction
See https://github.com/pjotrp/guix-notes

Foreign packages in GNU Guix – p. 20

Acknowledgements
In particular Ludovic Courtès, Ricardo Wurmus, David
Thompson & Ben Woodcroft for suporting Ruby
packaging and the ruby-build-system
The GNU and GNU Guix communities (many, many)
Prof. Rob W. Williams, UTHSC
(http://genenetwork.org/)

Foreign packages in GNU Guix – p. 21