Tweak cache-buildtrees option
This tweaks the recently merged cache-buildtrees
option (#896 (closed), !1135 (merged)) based on a discussion on IRC.
-
Drop supportAdd disclaimer forcache-buildtrees=never
Not caching the buildtree for failed builds breaks basic core functionality such as dropping into a shell in the failed build sandbox.
-
Rename
cache-buildtrees
option valuefailure
toauto
We anticipate other cases than build failures where buildtree caching will be required. E.g., incremental workspace build with remote execution. Or running tests in a buildtree in parallel with the build of reverse dependencies.
This renames the option value
failure
to the more genericauto
to cover these other cases as well. -
Change default of
cache-buildtrees
option toauto
Caching buildtrees may significantly increase CAS disk usage. Change the default to cache buildtrees only when required for core functionality.