daemon: Clarify ‘--check’ error when outputs are missing.

Drop the confusing ‘invalid’ jargon and display a hint like we do
for ‘--fallback’.

* nix/libstore/build.cc (DerivationGoal::outputsSubstituted): Rewrite error message.

diff --git a/nix/libstore/build.cc b/nix/libstore/build.cc
index 9305208..006e4eb 100644 (file)
--- a/nix/libstore/build.cc
+++ b/nix/libstore/build.cc
@@ -979,7 +979,7 @@ void DerivationGoal::outputsSubstituted()
         return;
     }
     if (buildMode == bmCheck && nrInvalid > 0)
-        throw Error(format("some outputs of `%1%' are not valid, so checking is not possible") % drvPath);
+        throw Error(format("`%1%' is missing outputs; build it normally before using `--check'") % drvPath);
 
     /* Otherwise, at least one of the output paths could not be
        produced using a substitute.  So we have to build instead. */