Comment 6 for bug 1315143

I don't see how it is possible to justify this kind of change in a LTS release. This proposal ignores the whole point of what a LTS release is: version stability is the default. The above suggestion doesn't even belong in trusty-backports, never mind trusty-proposed or trusty-updates.

Putting this change into the default repos will, by definition, break existing system deployments. You cannot swap out ruby1.9.1 with ruby2.0 without breaking the ABI of native code or breaking parts of the Ruby API on which applications may currently depend. This is directly in conflict with LTS goals.

There are other possibilities, such as the following change steps:

1. make the binary 'ruby'/'ruby1.9.1'/'ruby2.0' package indirect through alternatives, which would allow a much easier way to swap out (this is something that should be propagated forward to newer releases)

2. drop the dependency from 'ruby2.0' to 'ruby' (which then depends on 'ruby1.9.1')

This will give you a less painful way to change the version desired via update-alternatives.

Otherwise, as an alternative, a PPA could provide a replacement for ruby-defaults which, simply symlinks to the desired version and replaces/supersedes the 'ruby' binary package. To do this, the Utopic source package could be pulled down, edited to remove references to 'ruby2.1', and rebuilt for Trusty.

As-is, this recommendation is a non-starter. Consider the above suggestions instead.