It turns out that installing therubytracer, with dependency on old v8, even
when using source libv8 version is problematic.
(see
http://stackoverflow.com/questions/21666379/problems-installing-gitlab-on-odroid-v8-lib-not-available).
But wait, rails does not even need therubytracer, just any kind of javascript
server side execution framework like nodejs. Well just use that, as also
suggested from different internet sources (look link above), it works just
fine.
I had to make several adjustments to make it work with nixos:
* Replace relative config file lookups with ENV variable.
* Modify gitlab-shell to not clear then environment when running
pre-receive.
* Modify gitlab-shell to write some environment variables into
the .authorized_keys file to make sure gitlab-shell reads the
correct config file.
* Log unicorn output to syslog.
I tried various ways of adding a syslog package but the bundler would
not pick them up. Please fix in a better way if possible.
* Gitlab-runner program wrapper.
This is useful to run e.g. backups etc. with the correct
environment set up.