In fact, it does break builds. I've seen it personally with several Go libraries: they drop support for e.g. Go 1.12 in some minor version and then suddenly "go

In fact, it does break builds. I've seen it personally with several Go libraries: they drop support for e.g. Go 1.12 in some minor version and then suddenly "go install ./..." step in your CI stops to work. And since we're talking about Go 1.12, that is, pre-module days, fixing that entailed either a) upgrading your whole project to use modules; b) changing the build pipeline to explicitly check out the last working version of the library's repository into GOPATH in the pre-build step. This is particularly nasty when it happens in mostly stable, rarely-updated internal projects because what was supposed to be a 5-minute, 3-line update turns into a several hours long wrangling match. Apparently, the code does rot and rust or something.