1) It's a resource hog. Big time.
2) It's incredibly hard to set up. The installation instructions and the development instructions are essentially the same. Key point, an end user should never have to `bundle install`, ever.
We enjoy using it, but to new users I would recommend looking into gitbucket
https://github.com/takezoe/gitbucket
written in scala and no install necessary!
Oh... it's made in ruby.
https://github.com/gitlabhq/gitlabhq/tree/master/app/control...
self comment: this post isn't gonna end well :P
It could (and should) be more streamlined, I admit, but using diff et al. on the two affected configuration files makes the process fast. One could do it by hand w/o issues, but I wouldn't like it.
(Late) Edit: any problems I've ever had with upgrades have been related to not properly adjusting settings when moving new config files around. For example, in upgrading to 6.3 I failed to copy over my custom listen lines in unicorn for a non-standard port.
IMHO GitLab is easy to set up compared to something like Postfix. Making a GitLab server do what it's supposed to do is straightforward. You just follow all the steps. Making Postfix work as a proper mail server is kinda a mess.
[1]: https://github.com/phunehehe/chef-cookbooks/tree/master/gitl...
Heh, I feel exactly the opposite.