[xnickb]

Build caching is nice until you have to disable it because it broke something somewhere. At which point it becomes very hard to turn it back on.

In other words, one needs to have absolute trust in such tools to be able to rely on them.

[gertop]

I've never had an issue with ccache and I've been using it forever. Are you using it over a networked filesystem or something like that for it to become confused about what needs recompiling?