* Hack around those SQLite timeouts: just retry the transaction.

src/lib/Hydra/Controller/Build.pm

@@ -273,7 +273,7 @@ sub restart : Chained('build') PathPart Args(0) {
 
     requireProjectOwner($c, $build->project);
 
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         error($c, "This build cannot be restarted.")
             unless $build->finished &&
               ($build->resultInfo->buildstatus == 3 ||
@@ -304,7 +304,7 @@ sub cancel : Chained('build') PathPart Args(0) {
 
     requireProjectOwner($c, $build->project);
 
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         error($c, "This build cannot be cancelled.")
             if $build->finished || $build->schedulingInfo->busy;
 
@@ -340,7 +340,7 @@ sub keep : Chained('build') PathPart Args(1) {
 
     registerRoot $build->outpath if $newStatus == 1;
 
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         $build->resultInfo->update({keep => int $newStatus});
     });
 

src/lib/Hydra/Controller/Jobset.pm

@@ -64,7 +64,7 @@ sub submit : Chained('jobset') PathPart Args(0) {
     requireProjectOwner($c, $c->stash->{project});
     requirePost($c);
     
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         updateJobset($c, $c->stash->{jobset});
     });
 
@@ -79,7 +79,7 @@ sub delete : Chained('jobset') PathPart Args(0) {
     requireProjectOwner($c, $c->stash->{project});
     requirePost($c);
     
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         $c->stash->{jobset}->delete;
     });
     

src/lib/Hydra/Controller/Project.pm

@@ -44,7 +44,7 @@ sub submit : Chained('project') PathPart Args(0) {
     requireProjectOwner($c, $c->stash->{project});
     requirePost($c);
     
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         updateProject($c, $c->stash->{project});
     });
     
@@ -58,7 +58,7 @@ sub delete : Chained('project') PathPart Args(0) {
     requireProjectOwner($c, $c->stash->{project});
     requirePost($c);
     
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         $c->stash->{project}->delete;
     });
     
@@ -94,7 +94,7 @@ sub create_submit : Path('/create-project/submit') {
 
     my $projectName = trim $c->request->params->{name};
     
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         # Note: $projectName is validated in updateProject,
         # which will abort the transaction if the name isn't
         # valid.  Idem for the owner.
@@ -127,7 +127,7 @@ sub create_jobset_submit : Chained('project') PathPart('create-jobset/submit') A
     
     my $jobsetName = trim $c->request->params->{name};
 
-    $c->model('DB')->schema->txn_do(sub {
+    txn_do($c->model('DB')->schema, sub {
         # Note: $jobsetName is validated in updateProject, which will
         # abort the transaction if the name isn't valid.
         my $jobset = $c->stash->{project}->jobsets->create(

src/lib/Hydra/Controller/Root.pm

@@ -146,14 +146,14 @@ sub releases :Local {
         }
 
         elsif ($subcommand eq "submit") {
-            $c->model('DB')->schema->txn_do(sub {
+            txn_do($c->model('DB')->schema, sub {
                 updateReleaseSet($c, $releaseSet);
             });
             return $c->res->redirect($c->uri_for("/releases", $projectName, $releaseSet->name));
         }
 
         elsif ($subcommand eq "delete") {
-            $c->model('DB')->schema->txn_do(sub {
+            txn_do($c->model('DB')->schema, sub {
                 $releaseSet->delete;
             });
             return $c->res->redirect($c->uri_for($c->controller('Project')->action_for('view'), [$project->name]));
@@ -181,7 +181,7 @@ sub create_releaseset :Local {
 
     if (defined $subcommand && $subcommand eq "submit") {
         my $releaseSetName = $c->request->params->{name};
-        $c->model('DB')->schema->txn_do(sub {
+        txn_do($c->model('DB')->schema, sub {
             # Note: $releaseSetName is validated in updateProject,
             # which will abort the transaction if the name isn't
             # valid.

src/lib/Hydra/Helper/Nix.pm

@@ -8,7 +8,7 @@ use File::Basename;
 our @ISA = qw(Exporter);
 our @EXPORT = qw(
     isValidPath queryPathInfo
-    getHydraPath getHydraDBPath openHydraDB
+    getHydraPath getHydraDBPath openHydraDB txn_do
     registerRoot getGCRootsDir gcRootFor
     getPrimaryBuildsForReleaseSet getRelease getLatestSuccessfulRelease );
 
@@ -78,6 +78,21 @@ sub openHydraDB {
 }
 
 
+# Awful hack to handle timeouts in SQLite: just retry the transaction.
+# DBD::SQLite *has* a 30 second retry window, but apparently it
+# doesn't work.
+sub txn_do {
+    my ($db, $coderef) = @_;
+    while (1) {
+        eval {
+            $db->txn_do($coderef);
+        };
+        last if !$@;
+        die $@ unless $@ =~ "database is locked";
+    }
+}
+
+
 sub getGCRootsDir {
     die unless defined $ENV{LOGNAME};
     my $dir = "/nix/var/nix/gcroots/per-user/$ENV{LOGNAME}/hydra-roots";