On Fri, Aug 25, 2023 at 10:46:29AM +0300, Michael Tokarev wrote: > 24.08.2023 19:38, Alex Bennée wrote: > > From: Daniel P. Berrangé <berra...@redhat.com> > > > > The `ccache` tool can be very effective at reducing compilation times > > when re-running pipelines with only minor changes each time. For example > > a fresh 'build-system-fedora' job will typically take 20 minutes on the > > gitlab.com shared runners. With ccache this is reduced to as little as > > 6 minutes. > > I've been using ccache when building qemu in debian, for quite a while. > > The problem here, in the way qemu build system works, is that the cache > is hugely dependent on the path to the source. You change just one char > in there (/build/qemu/v8.1.0/ => /build/qemu/v8.1.1) and whole cache becomes > unusable, it all gets compiled anew. This is because qemu build sys uses > absolute file names when building, and this is detected by ccache, so > the source dir gets mixed into the hash together with gcc version and > other things. > > Dunno how well this will work in the qemu ci though.
Should be fine, as gitlab always checks out code in a fixed directory name matching the git repo name. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|