[scl.org] How to migrate to CentOS builds

[Honza Horak]

Currently, all the collections from RHSCL 2.1 have been released and 
announced. The website softwarecollections.org already includes steps to 
install those SCLs by running `yum install centos-release-scl-rh`.

However, the original repo packages are still there as well, because 
removing them would break users' settings (as we saw recently when the 
website got down). I'd like to find out a way to migrate to CentOS builds.

Many users use the repository packages from scl.org now, so simply 
removing those packages from scl.org right now is not an option. One 
idea with a relative schedule could be:

day 0: make the repository packages deprecated by adding a comment about 
it on scl.org (+ make some noise around it on ML, twitter, blogs...)
day 0+30: hide the repository packages on scl.org and only show `yum 
install centos-release-scl-rh` there
day 0+90: remove the repository packages

This way people who care should have enough time to move their 
infrastructure to using `yum install centos-release-scl-rh` instead of 
`yum install 
https://www.softwarecollections.org/.../rhscl-<scl>-epel-7-x86_64.noarch.rpm`, 
but those who wouldn't notice would have problems.

Another way would be replacing the repository packages by empty RPMs 
that would include centos-release-scl-rh package. This way the movement 
would be transparent for all users, but I'm not sure whether this is a 
good way to go, because people would start using another builds without 
notice. Well, at least it shouldn't break anything.

I'd like to hear any opinions, or other alternatives, especially from 
SCL users.

Thanks!
Honza