diff --git a/doc/manual/release-notes/rl-2.0.xml b/doc/manual/release-notes/rl-2.0.xml
index 0d485c36..32cdb1d0 100644
--- a/doc/manual/release-notes/rl-2.0.xml
+++ b/doc/manual/release-notes/rl-2.0.xml
@@ -99,11 +99,11 @@
- New build mode nix-build --hash that
- builds a derivation, computes the hash of the output, and moves
- the output to the store path corresponding to what a fixed-output
- derivation with that hash would produce.
- (Add docs and examples; see d367b8e7875161e655deaa96bf8a5dd0bcf8229e)
+ If a fixed-output derivation produces a result with an
+ incorrect hash, the output path will be moved to the location
+ corresponding to the actual hash and registered as valid. Thus, a
+ subsequent build of the fixed-output derivation with the correct
+ hash is unnecessary.
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index cca51f17..d4b93b51 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1124,11 +1124,6 @@ void DerivationGoal::haveDerivation()
return;
}
- /* Reject doing a hash build of anything other than a fixed-output
- derivation. */
- if (buildMode == bmHash && !drv->isFixedOutput())
- throw Error("cannot do a hash build of non-fixed-output derivation '%1%'", drvPath);
-
/* We are first going to try to create the invalid output paths
through substitutes. If that doesn't work, we'll build
them. */
@@ -1320,9 +1315,7 @@ void DerivationGoal::inputsRealised()
allPaths.insert(inputPaths.begin(), inputPaths.end());
/* Is this a fixed-output derivation? */
- fixedOutput = true;
- for (auto & i : drv->outputs)
- if (i.second.hash == "") fixedOutput = false;
+ fixedOutput = drv->isFixedOutput();
/* Don't repeat fixed-output derivations since they're already
verified by their output hash.*/
@@ -3019,6 +3012,8 @@ void DerivationGoal::registerOutputs()
bool runDiffHook = settings.runDiffHook;
bool keepPreviousRound = settings.keepFailed || runDiffHook;
+ std::exception_ptr delayedException;
+
/* Check whether the output paths were created, and grep each
output path to determine what other paths it references. Also make all
output paths read-only. */
@@ -3093,7 +3088,7 @@ void DerivationGoal::registerOutputs()
/* Check that fixed-output derivations produced the right
outputs (i.e., the content hash should match the specified
hash). */
- if (i.second.hash != "") {
+ if (fixedOutput) {
bool recursive; Hash h;
i.second.parseHashInfo(recursive, h);
@@ -3109,27 +3104,34 @@ void DerivationGoal::registerOutputs()
/* Check the hash. In hash mode, move the path produced by
the derivation to its content-addressed location. */
Hash h2 = recursive ? hashPath(h.type, actualPath).first : hashFile(h.type, actualPath);
- if (buildMode == bmHash) {
- Path dest = worker.store.makeFixedOutputPath(recursive, h2, drv->env["name"]);
- printError(format("build produced path '%1%' with %2% hash '%3%'")
- % dest % printHashType(h.type) % printHash16or32(h2));
- if (worker.store.isValidPath(dest))
- return;
+
+ Path dest = worker.store.makeFixedOutputPath(recursive, h2, drv->env["name"]);
+
+ if (h != h2) {
+
+ /* Throw an error after registering the path as
+ valid. */
+ delayedException = std::make_exception_ptr(
+ BuildError("fixed-output derivation produced path '%s' with %s hash '%s' instead of the expected hash '%s'",
+ dest, printHashType(h.type), printHash16or32(h2), printHash16or32(h)));
+
Path actualDest = worker.store.toRealPath(dest);
+
+ if (worker.store.isValidPath(dest))
+ std::rethrow_exception(delayedException);
+
if (actualPath != actualDest) {
PathLocks outputLocks({actualDest});
deletePath(actualDest);
if (rename(actualPath.c_str(), actualDest.c_str()) == -1)
throw SysError(format("moving '%1%' to '%2%'") % actualPath % dest);
}
+
path = dest;
actualPath = actualDest;
- } else {
- if (h != h2)
- throw BuildError(
- format("output path '%1%' has %2% hash '%3%' when '%4%' was expected")
- % path % i.second.hashAlgo % printHash16or32(h2) % printHash16or32(h));
}
+ else
+ assert(path == dest);
info.ca = makeFixedOutputCA(recursive, h2);
}
@@ -3306,6 +3308,11 @@ void DerivationGoal::registerOutputs()
paths referenced by each of them. If there are cycles in the
outputs, this will fail. */
worker.store.registerValidPaths(infos);
+
+ /* In case of a fixed-output derivation hash mismatch, throw an
+ exception now that we have registered the output as valid. */
+ if (delayedException)
+ std::rethrow_exception(delayedException);
}
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index b21d3dd8..70f23e1f 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -192,7 +192,7 @@ struct ValidPathInfo
typedef list ValidPathInfos;
-enum BuildMode { bmNormal, bmRepair, bmCheck, bmHash };
+enum BuildMode { bmNormal, bmRepair, bmCheck };
struct BuildResult
diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc
index 3d02276b..1581c282 100755
--- a/src/nix-build/nix-build.cc
+++ b/src/nix-build/nix-build.cc
@@ -167,9 +167,6 @@ void mainWrapped(int argc, char * * argv)
buildMode = bmRepair;
}
- else if (*arg == "--hash")
- buildMode = bmHash;
-
else if (*arg == "--run-env") // obsolete
runEnv = true;
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index f6f276dd..4fc3421c 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -122,7 +122,6 @@ static void opRealise(Strings opFlags, Strings opArgs)
if (i == "--dry-run") dryRun = true;
else if (i == "--repair") buildMode = bmRepair;
else if (i == "--check") buildMode = bmCheck;
- else if (i == "--hash") buildMode = bmHash;
else if (i == "--ignore-unknown") ignoreUnknown = true;
else throw UsageError(format("unknown flag '%1%'") % i);
diff --git a/tests/fixed.sh b/tests/fixed.sh
index cac3f0be..8f51403a 100644
--- a/tests/fixed.sh
+++ b/tests/fixed.sh
@@ -5,15 +5,22 @@ clearStore
export IMPURE_VAR1=foo
export IMPURE_VAR2=bar
+path=$(nix-store -q $(nix-instantiate fixed.nix -A good.0))
+
+echo 'testing bad...'
+nix-build fixed.nix -A bad --no-out-link && fail "should fail"
+
+# Building with the bad hash should produce the "good" output path as
+# a side-effect.
+[[ -e $path ]]
+nix path-info --json $path | grep fixed:md5:2qk15sxzzjlnpjk9brn7j8ppcd
+
echo 'testing good...'
nix-build fixed.nix -A good --no-out-link
echo 'testing good2...'
nix-build fixed.nix -A good2 --no-out-link
-echo 'testing bad...'
-nix-build fixed.nix -A bad --no-out-link && fail "should fail"
-
echo 'testing reallyBad...'
nix-instantiate fixed.nix -A reallyBad && fail "should fail"