* Negative caching: don't perform a build if a dependency already

failed in a previous build.  This is essential for Nixpkgs: we don't
  want to keep doing the same failed dependency (say, Glibc) over and
  over again for a few hundred jobs.

src/lib/Hydra/Schema.pm

@@ -8,8 +8,8 @@ use base 'DBIx::Class::Schema';
 __PACKAGE__->load_classes;
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:hRwus0A1vxnFCzQxghFgTw
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:DQAmauNODAxmM2mF/AE2aQ
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/BuildInputs.pm

@@ -36,8 +36,8 @@ __PACKAGE__->belongs_to("build", "Hydra::Schema::Builds", { id => "build" });
 __PACKAGE__->belongs_to("dependency", "Hydra::Schema::Builds", { id => "dependency" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:H25BhHe9wbU6nj6fSKjZnw
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:L6NP/+9zhMg4TRw3w911rg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/BuildProducts.pm

@@ -35,8 +35,8 @@ __PACKAGE__->set_primary_key("build", "productnr");
 __PACKAGE__->belongs_to("build", "Hydra::Schema::Builds", { id => "build" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:rfkj/A+Li7Q0hWydqtJHAw
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:yTJRsclWIpHApRSLqyR06Q
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/BuildResultInfo.pm

@@ -26,14 +26,22 @@ __PACKAGE__->add_columns(
   { data_type => "text", is_nullable => 0, size => undef },
   "keep",
   { data_type => "integer", is_nullable => 0, size => undef },
+  "faileddepbuild",
+  { data_type => "integer", is_nullable => 0, size => undef },
+  "faileddepstepnr",
+  { data_type => "integer", is_nullable => 0, size => undef },
 );
 __PACKAGE__->set_primary_key("id");
 __PACKAGE__->belongs_to("id", "Hydra::Schema::Builds", { id => "id" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:wmL9881G+dZrgHKM83dHXw
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:o1XAUgKd15pN76Rs8aX+IA
 
+__PACKAGE__->belongs_to(
+  "failedDep",
+  "Hydra::Schema::BuildSteps",
+  { id => "faileddepbuild", stepnr => "faileddepstepnr" },
+);
 
-# You can replace this text with custom content, and it will be preserved on regeneration
 1;

src/lib/Hydra/Schema/BuildSchedulingInfo.pm

@@ -27,8 +27,8 @@ __PACKAGE__->set_primary_key("id");
 __PACKAGE__->belongs_to("id", "Hydra::Schema::Builds", { id => "id" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:6cTj5JovtTmtemvQjWtucQ
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:MeS9DLCs3kuhS4pTqfl4Lg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/BuildSteps.pm

@@ -35,9 +35,7 @@ __PACKAGE__->set_primary_key("id", "stepnr");
 __PACKAGE__->belongs_to("id", "Hydra::Schema::Builds", { id => "id" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:LyNlkn5XjBnLp7M4ipB/ZQ
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:nFSksz60oxcM1+nYqAdjzw
 
-
-# You can replace this text with custom content, and it will be preserved on regeneration
 1;

src/lib/Hydra/Schema/Builds.pm

@@ -76,8 +76,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:8U9CmcfeowLJVViKiR3n1g
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:p9SIzdyW9p4+eqwKwXzAdQ
 
 __PACKAGE__->has_many(dependents => 'Hydra::Schema::BuildInputs', 'dependency');
 

src/lib/Hydra/Schema/CachedPathInputs.pm

@@ -22,8 +22,8 @@ __PACKAGE__->add_columns(
 __PACKAGE__->set_primary_key("srcpath", "sha256hash");
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:+F3EiYsvXuOjnGDrkhLxng
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:zvTGb3qhlacSWzc0H+7dfg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/CachedSubversionInputs.pm

@@ -20,8 +20,8 @@ __PACKAGE__->add_columns(
 __PACKAGE__->set_primary_key("uri", "revision");
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:O0QvXjOulMVTjhW4rRHkmQ
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:TY8SHfWiBibwiG3WPkP8Mg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/JobsetInputAlts.pm

@@ -31,8 +31,8 @@ __PACKAGE__->belongs_to(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:qXh+0QbMUHIDmQCG9T5qdA
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:4iKXGIdrm56xZeHFxa/K4A
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/JobsetInputs.pm

@@ -43,8 +43,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:TUTdwfhSsFMKBXa/wKenOQ
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:rh03/olFXpMiTA+zhRYltg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/Jobsets.pm

@@ -50,8 +50,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:dVevQ8lPI2/IRpYoJgzLBA
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:IfDpZfiD9haRHLXGdkapGg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/Projects.pm

@@ -45,8 +45,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:Q5mSKzMxB9px2ja8NjK/9Q
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:7VRmssxrhgzfySJ6OGuhGg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/ReleaseSetJobs.pm

@@ -32,8 +32,8 @@ __PACKAGE__->belongs_to(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:+Ky8V3sZIgT22hgF27Y0cw
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:GdOtS3nLs7dwpArSdGob0w
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/ReleaseSets.pm

@@ -29,8 +29,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:f+4AnWTJsi4RDfxoJxECgw
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:lQymTkBv/Av2y6iYjvP5PQ
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/SystemTypes.pm

@@ -16,8 +16,8 @@ __PACKAGE__->add_columns(
 __PACKAGE__->set_primary_key("system");
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:Af/LU15/hpXngfrBrDMI/A
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:KZzTedcMG8IxkLgEEkdn9A
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/UserRoles.pm

@@ -17,8 +17,8 @@ __PACKAGE__->set_primary_key("username", "role");
 __PACKAGE__->belongs_to("username", "Hydra::Schema::Users", { username => "username" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:/yDlbFhRYDzf+0VHzygrhA
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:9YGxnZD9hLoJJ8b1aejBuA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/lib/Hydra/Schema/Users.pm

@@ -30,8 +30,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-06 14:20:12
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2009-03-09 18:05:06
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:d7M/Q6OucU9NUCSB5zZK7Q
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:HwKK4N8V5fzvR3XrKnrDEA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration

src/root/build.tt

@@ -43,6 +43,11 @@
         [% ELSIF build.resultInfo.buildstatus == 4 %]
           <img src="/static/images/failure.gif" alt="Failed" />
           <span class="error">Cancelled by user</span>
+        [% ELSIF build.resultInfo.buildstatus == 5 %]
+          <img src="/static/images/failure.gif" alt="Failed" />
+          <span class="error">Build inhibited because a dependency previously failed to build</span>
+          [% failedDep = build.resultInfo.failedDep %]
+          (namely, <a href="[% c.uri_for('/build' failedDep.id.id 'nixlog' failedDep.stepnr) %]"><tt>[% failedDep.outpath %]</tt></a>)
         [% ELSE %]
           <img src="/static/images/failure.gif" alt="Failed" />
           <span class="error">Build failed</span>
@@ -256,7 +261,7 @@
 [% IF build.finished %]
 
 
-[% IF build.resultInfo.errormsg %]
+[% IF build.resultInfo.errormsg && build.resultInfo.buildstatus != 5 %]
 
 <h2 id="nix-error">Nix error output</h2>
 

src/script/hydra_build.pl

@@ -25,11 +25,46 @@ sub doBuild {
 
     my $errormsg = undef;
 
+    my $failedDepBuild;
+    my $failedDepStepNr;
+    
     registerRoot $outPath;
     
     if (!isValidPath($outPath)) {
         $isCachedBuild = 0;
 
+        # Check whether a dependency of this build has previously
+        # failed.  If so, don't even bother to build, since it will
+        # fail anyway.  !!! Once Nix has negative caching, this code
+        # can go.
+
+        my @drvDeps = split '\n', `nix-store --query --requisites --include-outputs $drvPath`;
+        die "cannot query dependencies of `$drvPath': $?" if $? != 0;
+
+        @drvDeps = grep { $_ =~ /.drv$/ } @drvDeps;
+
+        my @drvOutputs = split '\n', `nix-store --query --outputs @drvDeps`;
+        die "cannot query outputs of the dependencies of `$drvPath': $?" if $? != 0;
+
+        foreach my $dep (@drvOutputs) {
+            # !!! This checks more than it has to, namely
+            # build-time-only dependencies of dependencies (which
+            # don't need to be built).  However, it shouldn't matter:
+            # if the dependency was built, then presumably *its*
+            # dependencies were built as well.
+            # !!! should disregard fixed-output derivations (?)
+            if (!isValidPath($dep)) {
+                my ($step) = $db->resultset('BuildSteps')->search(
+                    {outPath => $dep}, {rows => 1, order_by => "stopTime DESC"});
+                if (defined $step && $step->status != 0) {
+                    $buildStatus = 5;
+                    $failedDepBuild = $step->id->id;
+                    $failedDepStepNr = $step->stepnr;
+                    goto done;
+                }
+            }
+        }
+        
         # Do the build.
         $startTime = time();
 
@@ -161,8 +196,10 @@ sub doBuild {
         $errormsg = undef unless $buildStatus == 3;
     }
 
+  done:
+
     $db->txn_do(sub {
-        $build->({finished => 1, timestamp => time});
+        $build->update({finished => 1, timestamp => time});
 
         my $logPath = "/nix/var/log/nix/drvs/" . basename $drvPath;
         $logPath = undef unless -e $logPath;
@@ -184,6 +221,8 @@ sub doBuild {
             , logfile => $logPath
             , errormsg => $errormsg
             , releasename => $releaseName
+            , faileddepbuild => $failedDepBuild
+            , faileddepstepnr => $failedDepStepNr
             });
 
         if ($buildStatus == 0) {

src/sql/hydra.sql

@@ -62,6 +62,7 @@ create table BuildResultInfo (
     --   2 = build of some dependency failed
     --   3 = other failure (see errorMsg)
     --   4 = build cancelled (removed from queue; never built)
+    --   5 = build not done because a dependency failed previously
     buildStatus   integer,
 
     errorMsg      text, -- error message in case of a Nix failure
@@ -75,12 +76,16 @@ create table BuildResultInfo (
 
     keep          integer not null default 0, -- true means never garbage-collect the build output
 
+    -- If buildStatus == 5, the primary key of the failed build step.
+    failedDepBuild  integer,
+    failedDepStepNr integer,
+    
     foreign key   (id) references Builds(id) on delete cascade -- ignored by sqlite
 );
 
 
 create table BuildSteps (
-    id            integer not null,
+    id            integer not null, -- !!! rename to "build"
     stepnr        integer not null,
 
     type          integer not null, -- 0 = build, 1 = substitution