Adding BC checks on every repository

[Nyholm]

Im not sure if this is a good idea or not... We will not notice this on PullRequests anyways..

[atymic]

Is there a reason why it's done on each individual repo rather than when merging here (on the main one)?

[Nyholm]

Yes. Because if one package breaks BC the main build will be red.

It is fine that one package breaks BC (it might prepare for a new major release) but it is never okey for the main build to be red.