Re: Multiple versions

[Ricardo Wurmus <rekado@elephly.net>]

Dmitry Bogatov <KAction@gnu.org> writes:

>> I do the same with Ruby using profiles. I have any number of interpreters
>> installed for testing and any number of libraries using either guix or
>> the lib path with a profile in there.
>
> But how do you solve problem, that for example you want library foo-999.very.new,
> compiled with ruby-1.8, but they never existed at same time in guix
> package tree?

Then you can either look up the recipe for ruby-1.8 in the repository
history and copy it, or you create a fresh variant of the “ruby” package
with something like this:

    (define-public my-particular-ruby
      (package (inherit ruby)
        (version "1.8")
        (source (origin ...) ...)))

Here you adjust the version and the source, and bind this variant to a
name “my-particular-ruby”.

You can either put this expression in the “ruby.scm” module (e.g. in a
local branch), or maintain your own package module.  If you choose the
latter you’d have to tell Guix about it by pointing the environment
variable “GUIX_PACKAGE_PATH” at the path.

~~ Ricardo