Whereas `ContentAddressWithReferences` is a sum type complex because different
varieties support different notions of reference, and
`ContentAddressMethod` is a nested enum to support that,
`ContentAddress` can be a simple pair of a method and hash.
`ContentAddress` does not need to be a sum type on the outside because
the choice of method doesn't effect what type of hashes we can use.
Co-Authored-By: Cale Gibbard <cgibbard@gmail.com>
With the switch to C++20, the rules became more strict, and we can no
longer initialize base classes. Make them comments instead.
(BTW
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2287r1.html
this offers some new syntax for this use-case. Hopefully this will be
adopted and we can eventually use it.)
Fix#6209
When trying to run `nix log <installable>`, try first to resolve the derivation pointed to
by `<installable>` as it is the resolved one that holds the build log.
This has a couple of shortcomings:
1. It’s expensive as it requires re-reading the derivation
2. It’s brittle because if the derivation doesn’t exist anymore or can’t
be resolved (which is the case if any one of its build inputs is missing),
then we can’t access the log anymore
However, I don’t think we can do better (at least not right now).
The alternatives I see are:
1. Copy the build log for the un-resolved derivation. But that means a
lot of duplication
2. Store the results of the resolving in the db. Which might be the best
long-term solution, but leads to a whole new class of potential
issues.
Since 4806f2f6b0, we can't have paths with
references passed to builtins.{path,filterSource}. This prevents many cases
of those functions called on IFD outputs from working. Resolve this by
passing the references found in the original path to the added path.
This fixes a bug in the garbage collector where if a path
/nix/store/abcd-foo is valid, but we do a
isValidPath("/nix/store/abcd-foo.lock") first, then a negative entry
for /nix/store/abcd is added to pathInfoCache, so /nix/store/abcd-foo
is subsequently considered invalid and deleted.
Similar to the nar-info disk cache (and using the same db).
This makes rebuilds muuch faster.
- This works regardless of the ca-derivations experimental feature.
I could modify the logic to not touch the db if the flag isn’t there,
but given that this is a trash-able local cache, it doesn’t seem to be
really worth it.
- We could unify the `NARs` and `Realisation` tables to only have one
generic kv table. This is left as an exercise to the reader.
- I didn’t update the cache db version number as the new schema just
adds a new table to the previous one, so the db will be transparently
migrated and is backwards-compatible.
Fix#4746
