Add option to verify build determinism

Passing "--option build-repeat <N>" will cause every build to be
repeated N times. If the build output differs between any round, the
build is rejected, and the output paths are not registered as
valid. This is primarily useful to verify build determinism. (We
already had a --check option to repeat a previously succeeded
build. However, with --check, non-deterministic builds are registered
in the DB. Preventing that is useful for Hydra to ensure that
non-deterministic builds don't end up getting published at all.)

1 files changed, 11 insertions, 3 deletions

diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 485209d7a..9cc5fd45b 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -87,10 +87,17 @@ struct ValidPathInfo
     Path deriver;
     Hash hash;
     PathSet references;
-    time_t registrationTime;
-    unsigned long long narSize; // 0 = unknown
+    time_t registrationTime = 0;
+    unsigned long long narSize = 0; // 0 = unknown
     unsigned long long id; // internal use only
-    ValidPathInfo() : registrationTime(0), narSize(0) { }
+
+    bool operator == (const ValidPathInfo & i) const
+    {
+        return
+            path == i.path
+            && hash == i.hash
+            && references == i.references;
+    }
 };
 
 typedef list<ValidPathInfo> ValidPathInfos;
@@ -114,6 +121,7 @@ struct BuildResult
         MiscFailure,
         DependencyFailed,
         LogLimitExceeded,
+        NotDeterministic,
     } status = MiscFailure;
     std::string errorMsg;
     //time_t startTime = 0, stopTime = 0;