Make sure the following development libraries are installed before you start building ruby:
(The ruby configure, make and make install (i.e. building and installing) will not tell you anything about these missing libraries)
1) zlib-dev (I think the package name is zlib1g-dev) -- Needed when you try to install the rails gem. If this is not available you will get the following error when you try to install rails with the command :
gem install rails2) libssl-dev -- Needed when you try to run the inbuilt rails WEBrick server and load the first example app in the getting started guide. You will get an error of the type:
ERROR: Loading command: install (LoadError) no such file to load -- zlib
"LoadError: no such file to load -- openssl"In my case I did not have this library the first time I built ruby. So I followed the instructions given here to build the openssl-ruby module/binding.
After this I ran `make` and `make install` from the top ruby source directory. May be that was not necessary, but I did it anyways.
Also, I am guessing that if this package was available when I first built ruby then the openssl-ruby module would be built by default. If not there should be a configure option to enable this `feature`. The configure's help output does not provide any info on this (not even the --help=recursive option).
==== Upgrading from older ruby versions ====
Older ruby versions used the folder /usr/local/lib/ruby/site_ruby/
So you will have to get rid of the site_ruby folder (i.e. delete it) so that the gems are not searched for and used from a stale folder.
Not doing this might result in you not being able to run gem at all.