[chacham15]

Its an idealistic view which will almost certainly fail. Test suites, as much as we like to hope that they reflect real usage, mostly dont. A simple example: if function a gets changed from o(n) to o(n^2) but otherwise behaves identically, most test suites will still pass, but if a user has that function in its own inner loop you can go from o(n^2) to o(n^2^2) which can definitely break a lot of things (simple example: transaction was holding lock for too long and so the transaction was aborted). Being able to catch the above is a high bar for a test suite which I'm fairly confident most test suites are way below that.

[samatman]

You're allowed to fix bugs introduced by new releases, you know. It's called a patch release?

Is your claim that a release which introduces bad algorithmic complexity requires a major release to fix in semver? Who thinks this?

[pgphn]

Right. Theres a difference between, “oh no, sorry, WE should fix that in the next patch” vs, “oh no, sorry, YOU should accommodate this incompatibility with a change on your side.”