Honestly the only code base I've seen which does this is Google's Chromium stuff; by default, it will download a pre-built Clang as well as a Debian sysroot. IM

Honestly the only code base I've seen which does this is Google's Chromium stuff; by default, it will download a pre-built Clang as well as a Debian sysroot. IMO, it's completely insane and has always been a giant pain in the ass. Maybe it's warranted for something as complex as Chromium but I really don't think it's the right choice for some 10kLOC FOSS project.