I'm working with a legacy rails system. We're still stuck on Rails 2.3.2 (yes really) and ruby 1.8.7 (it's better than 1.8.6 which we were on only a few months back).
I've just been given a new computer at work (finally) and it has ubuntu 12.04 - and I was trying to set it up with a rails stack. For which I can strongly recommend Ryan Bigg's howto article: Ubuntu, Ruby, RVM, Rails, and You
I got through the tutorial ok, happily installed ruby 1.9.3... but when I tried to install 1.8.7, I hit a snag.
triton:[~]% rvm install 1.8.7 Searching for binary rubies, this might take some time. No binary rubies available for: ubuntu/12.04/x86_64/ruby-1.8.7-p374. Continuing with compilation. Please read 'rvm help mount' to get more information on binary rubies. You requested building with 'gcc-4.4' but it is not in your path.
According to rvm, you can list the set of available rubies using rvm remote which gave me:
# Rubies available for 'ubuntu/12.04/x86_64': ruby-1.9.3-p194 ruby-1.9.3-p286 ruby-1.9.3-p327 ruby-1.9.3-p362 ruby-1.9.3-p374 ruby-1.9.3-p392 ruby-1.9.3-p429 ruby-1.9.3-p448 ruby-2.0.0-p0 ruby-2.0.0-p195 ruby-2.0.0-p247
Now, I know 1.8.7 is ancient news, but I didn't think they'd drop support for it so entirely.
I went wandering about looking for a way to specify an older repository - perhaps the 10.04 repo would still have 1.8.7 in a useable format...
Turns out I'd just made a simple mistake, easily rectified.
The important clue was in the last line of the result for rvm install:
You requested building with 'gcc-4.4' but it is not in your path.
I'd copied a whole bunch of things across to the new 'puter, including my .zshrc file - which is what was specifying the gcc version (can't remember why). And on the new 'puter I had gcc version 4.6 but my .zshrc (copied from my previous computer) was pointing at this older version.
Because of this small mistake, rvm thought I didn't have a c-compiler. Which means that rvm wasn't able to install any rubies from source - only pre-compiled rubies - which means it was restricted to only those already pre-compiled for my platform (ie 64-bit ubuntu 12.04).
When I fixed the gcc line in my .zshrc - rvm was able to figure out how to install+compile source-code rubies - including v1.8.7