From 7e162c69fe6cbfb929b5356a7df9de5c25c22565 Mon Sep 17 00:00:00 2001 From: Robert Hensing Date: Mon, 14 Nov 2022 16:26:20 +0100 Subject: [PATCH] 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. --- src/libstore/build/derivation-goal.cc | 30 +++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc index 41d2e2a1c..00e375fe9 100644 --- a/src/libstore/build/derivation-goal.cc +++ b/src/libstore/build/derivation-goal.cc @@ -528,13 +528,31 @@ 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 - throw Error( - "derivation '%s' requires non-existent output '%s' from input derivation '%s'", - worker.store.printStorePath(drvPath), j, worker.store.printStorePath(depDrvPath)); + } + 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); + } + } } }