* Cut off builds after half an hour of apparent inactivity. This

should really be configurable.

src/Hydra/script/hydra_build.pl

@@ -36,7 +36,7 @@ sub doBuild {
         # Run Nix to perform the build, and monitor the stderr output
         # to get notifications about specific build steps, the
         # associated log files, etc.
-        my $cmd = "nix-store --keep-going --no-build-output " .
+        my $cmd = "nix-store --max-silent-time 1800 --keep-going --no-build-output " .
             "--log-type flat --print-build-trace --realise $drvPath 2>&1";
 
         my $buildStepNr = 1;