I just tried it, on my PC it takes cargo 0.3 seconds to start compiling the first of 309 dependencies in a clean Bevy repo. The entire compilation takes 31 seconds, and that's the best case with lots of multithreading and all packages already downloaded. That's close enough to "free" for me.

1/3 of a second for a build that has already cached all dependencies means I was correct that it's not free and you were being dismissive when you said it had nothing to do with build times.

If you want to argue that it's a minimal amount of time then argue that instead of what you've been arguing.

The latency you’re arguing over is probably more to do with rustup selecting the right cargo and exec-ing that than dependency resolution. It’s heavier weight than it should be due to history reasons.