Awesome! Feel free to make an issue and potentially a PR and I’ll see this fixed and merged asap. The thread key, like the appendix, isn’t critical to anything at the moment and can safely be removed.
Hey Lars,
On a separate note and out of curiosity, how are you creating such an environment, with a particular version of gcc and the like? Sounds like virtualenv, but for system packages, and I want in!
Hey Marcus,
It’s a deeply configured version of Rez were all packages including gcc are build from .tar.gz using cmake’s build external system.
https://github.com/nerdvegas/rez/tree/master/repository/gcc/4.8.2
Ah. Was afraid of that. 
Do you think it is be possible to setup by hand somehow? What high level steps does it involve, apart from compiling things and setting environment variables?
you can set it up by hand but rez makes most of it much easier.
the link i send above is really the main set of things you will want to start off with. the reason i said its a deeply Configured version of rez is that I started the process of generating these external repositories for rez is implemented them. however our technique is pretty much the same.
protip: ones you have compiled GCC remove it from your base install. that way it cannot get confused when it’s trying to compile any other packages. Linux has a nasty habit of using hardcoded GCC paths.