dev-cpp/yaml-cpp from 0.7.0 is not backward compatible with 0.6.3, so it should go to another slot Reproducible: Always Steps to Reproduce: Actually my working project failed to compile after upgrade to 0.7.0-r1, as lib's classes signatures changed. Not sure, if I can explain any better.
https://github.com/jbeder/yaml-cpp/compare/yaml-cpp-0.6.3...yaml-cpp-0.7.0
include/yaml-cpp/exceptions
When possible, typically it's better to try to avoid slotting and instead ensure packages are compatible with the new one so we can move on (especially on 0.x.x semver packages without a stable API, we'll just be accumulating slots without real support). Any chances to just migrate your project instead? Same would go for any ::gentoo packages failing with this.
My project will be fine, I fixed it already. If there is no gentoo packages that rely on changed part of the API, and it is not worth slotting, then bug can be closed.
Slots are for cases when both versions can be installed simultaneously. This package installs yaml-cpp.pc, which presumably clients use via pkg-config. The both packages can't install the same .pc file, so at least one of these types of clients will be broken. Unless we go the python eclasses way, but no.
