Kristofer Karlsson [off-list ref] writes:
Then I started adding a second env variable. That worked
and it was not _too_ messy though I realized it was a bit
redundant. We can simply deduce the real object directory
from the quarantine directory -- it's the parent, based on
how tmp_objdir_create() works today -- so I built my preliminary
v2 on that.
It feels like a slightly icky assumption to make, but it
feels safe since I added tests to cover it, and does not seem
possible to override outside of git itself.
Well, as Patrick said elsewhere recently, the entire "since we are
borrowing from this alternate object store, it would be nice if we
can assume there is some ref storage that tells us which objects in
it are 'complete', but because the alternate object store interface
does not define such a set of refs associated with it, let's just
assume the refs/ directory sitting immediately next to the objects/
directory is such a hierarchy" is an icky hack that is crumbling,
given that the alternate object store may be a part of a repository
that uses reftable. It also is troublesome to "borrow" from a
shallow clone where their grafts are part of the mechanism they use
to avoid stepping outside the set of available objects, which the
alternate object store mechanism does not "borrow", as far as I
recall.
So until we figure out how to fix these icky points, it probably is
not a huge deal to pile on another icky assumption as a short-term
measure.