derivation-goal: Fix requires non-existing output error

It occurred when a output of the dependency was already available,
so it didn't need rebuilding and didn't get added to the
inputDrvOutputs.
This process-related info wasn't suitable for the purpose of finding
the actual input paths for the builder. It is better to do this in
absolute terms by querying the store.
This commit is contained in:
Robert Hensing 2022-11-14 16:26:20 +01:00
parent 0efc314d4d
commit 7e162c69fe

View file

@ -528,14 +528,32 @@ void DerivationGoal::inputsRealised()
/* Add the relevant output closures of the input derivation
`i' as input paths. Only add the closures of output paths
that are specified as inputs. */
for (auto & j : wantedDepOutputs)
if (auto outPath = get(inputDrvOutputs, { depDrvPath, j }))
for (auto & j : wantedDepOutputs) {
/* TODO (impure derivations-induced tech debt):
Tracking input derivation outputs statefully through the
goals is error prone and has led to bugs.
For a robust nix, we need to move towards the `else` branch,
which does not rely on goal state to match up with the
reality of the store, which is our real source of truth.
However, the impure derivations feature still relies on this
fragile way of doing things, because its builds do not have
a representation in the store, which is a usability problem
in itself */
if (auto outPath = get(inputDrvOutputs, { depDrvPath, j })) {
worker.store.computeFSClosure(*outPath, inputPaths);
else
}
else {
auto outMap = worker.evalStore.queryDerivationOutputMap(depDrvPath);
auto outMapPath = outMap.find(j);
if (outMapPath == outMap.end()) {
throw Error(
"derivation '%s' requires non-existent output '%s' from input derivation '%s'",
worker.store.printStorePath(drvPath), j, worker.store.printStorePath(depDrvPath));
}
worker.store.computeFSClosure(outMapPath->second, inputPaths);
}
}
}
}
/* Second, the input sources. */