I did some experimenting with ccache 3.0 to speed up package building in scratchbox:
http://bit.ly/9UFbAM

Using a cache for compilation units is very nice indeed. The only thing to look out for is special cases where the cache is used a bit too much leading to old compilation units getting linked into the new binary.

These special cases typically arise with complicated build situations and generate serious headaches while debugging until one actually checks what was pulled from the cache and what was re-compiled.

BTDTGTT.

I agree, this is exactly why I had earlier disabled ccache from my system - I had problems linking that took a long time to figure out. Nowadays I will be using ccache but making sure to disable it whenever I encounter weird errors, before trying anything else.