Typically in an edit/compile cycle you'd only compile your dependencies once for each build type (check, debug, release). Unless you change a dependency's feature flag, the compiler will just re-use what's already been compiled.
If you clean your build folder, things will need to be rebuilt from scratch. Likewise if you change your compiler version.
Re:A Few More Reasons Rust Compiles Slowly
by alkonaut on Tuesday June 30, 2020 @11:55AM
(#23691353)
It seems a CI system should be able to work the same way and cache the dependencies just like a local build.
If it does, then the long compile times are almost never encountered for neither developers nor CI. So are they really problematic?
What is it that triggers such a "full" build though? Obviously in some CI scenarios you might start from scratch, but in an edit/compile cycle, you'd never be hitting those 5 minutes, correct?