> Allow building against packages without installing them.
A partial staged update system would work the best. I should be able to schedule the build of several new packages, have them built into a sandbox, and have new compilations use the sandbox first and then fallback to the system through a union, and then once everything is build finally package up all the pieces and then move them out of the sandbox and into the system at large.
You could make all gentoo updates transactional that way which would be a huge boon in many other ways.
You definitely don't want all upgrades to be transactional, at least not without being able to reuse partial results. E.g. having to rebuild an llvm update because some other package failed to build would suck.
Presumably one wouldn't throw away the built packages if some other build fails just because we're delaying installing the packages to `/` until later.
A partial staged update system would work the best. I should be able to schedule the build of several new packages, have them built into a sandbox, and have new compilations use the sandbox first and then fallback to the system through a union, and then once everything is build finally package up all the pieces and then move them out of the sandbox and into the system at large.
You could make all gentoo updates transactional that way which would be a huge boon in many other ways.