On nix-env -qa -f '<nixpkgs>', this reduces maximum RSS by 20970 KiB
and runtime by 0.8%. This is mostly because we're not parsing the hash
part as a hash anymore (just validating that it consists of base-32
characters).
Also, replace storePathToHash() by StorePath::hashPart().
E.g. instead of
error: --- BuildError ----------------------------------------------- nix
builder for '/nix/store/03nk0a3n8h2948k4lqfgnnmym7knkcma-foo.drv' failed with exit code 1
error: --- Error ---------------------------------------------------- nix
build of '/nix/store/03nk0a3n8h2948k4lqfgnnmym7knkcma-foo.drv' failed
we now get
error: --- Error ---------------------------------------------------- nix
builder for '/nix/store/03nk0a3n8h2948k4lqfgnnmym7knkcma-foo.drv' failed with exit code 1
Originally, the test was only checking for different “real” storeDir.
That’s an easy case to handle, but the much harder one is if different
virtual store dirs are used. To do this, we need the SubstitutionGoal
to know about the ca, so it can recalculate the path to copy it over.
An important note here is that the store path passed to copyStorePath
needs to be one for srcStore - so that queryPathInfo works properly.
This also adds an error message when the store path from queryPathInfo
is different from the one we requested.
We can’t use custom name here because different names will have
different store paths. This is a limitation of the Store API’s
reliance on store paths.
We might be able to get around the above in the future by using a
dummy name for certain fixed output paths.
Substituters can substitute from one store dir to another with a
little bit of help. The store api just needs to have a CA so it can
recompute the store path based on the new store dir. We can only do
this for fixed output derivations with no references, though.
This function was used in only one place, where it could easily be
replaced by readDerivation() since it's not
performance-critical. (This function appears to have been modelled
after queryDerivationOutputs(), which exists only to make the garbage
collector faster.)
