From 63306aaf5a6e96481e40fd2975875e0bb9ad664a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Thu, 9 Apr 2015 17:35:04 +0200
Subject: [PATCH] hydra-evaluator: Add some debug code

---
 src/lib/Hydra/Helper/AddBuilds.pm | 16 +++++++++++++---
 src/script/hydra-evaluator        | 22 ++++++++++++++++++----
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/src/lib/Hydra/Helper/AddBuilds.pm b/src/lib/Hydra/Helper/AddBuilds.pm
index e43785d2..e01cfd04 100644
--- a/src/lib/Hydra/Helper/AddBuilds.pm
+++ b/src/lib/Hydra/Helper/AddBuilds.pm
@@ -330,10 +330,20 @@ sub evalJobs {
     my $nixExprFullPath = $nixExprInput->{storePath} . "/" . $nixExprPath;
 
     my $evaluator = ($exprType eq "guile") ? "hydra-eval-guile-jobs" : "hydra-eval-jobs";
-    print STDERR "evaluator ${evaluator}\n";
 
-    (my $res, my $jobsJSON, my $stderr) = captureStdoutStderr(10800,
-        $evaluator, $nixExprFullPath, "--gc-roots-dir", getGCRootsDir, "-j", 1, inputsToArgs($inputInfo, $exprType));
+    my @cmd = ($evaluator, $nixExprFullPath, "--gc-roots-dir", getGCRootsDir, "-j", 1, inputsToArgs($inputInfo, $exprType));
+
+    if (defined $ENV{'HYDRA_DEBUG'}) {
+        sub escape {
+            my $s = $_;
+            $s =~ s/'/'\\''/g;
+            return "'" . $s . "'";
+        }
+        my @escaped = map escape, @cmd;
+        print STDERR "evaluator: @escaped\n";
+    }
+
+    (my $res, my $jobsJSON, my $stderr) = captureStdoutStderr(10800, @cmd);
     die "$evaluator returned " . ($res & 127 ? "signal $res" : "exit code " . ($res >> 8))
         . ":\n" . ($stderr ? $stderr : "(no output)\n")
         if $res;
diff --git a/src/script/hydra-evaluator b/src/script/hydra-evaluator
index 51843770..52d7e9af 100755
--- a/src/script/hydra-evaluator
+++ b/src/script/hydra-evaluator
@@ -25,6 +25,7 @@ my $plugins = [Hydra::Plugin->instantiate(db => $db, config => $config)];
 # Don't check a jobset more than once every five minutes.
 my $minCheckInterval = 5 * 60;
 
+my $dryRun = defined $ENV{'HYDRA_DRY_RUN'};
 
 
 sub fetchInputs {
@@ -112,7 +113,7 @@ sub checkJobsetWrapped {
         my $msg = $@;
         print STDERR $msg;
         txn_do($db, sub {
-            $jobset->update({ lastcheckedtime => time, fetcherrormsg => $msg });
+            $jobset->update({ lastcheckedtime => time, fetcherrormsg => $msg }) if !$dryRun;
         });
         return;
     }
@@ -124,7 +125,7 @@ sub checkJobsetWrapped {
     my @args = ($jobset->nixexprinput, $jobset->nixexprpath, inputsToArgs($inputInfo, $exprType));
     my $argsHash = sha256_hex("@args");
     my $prevEval = getPrevJobsetEval($db, $jobset, 0);
-    if (defined $prevEval && $prevEval->hash eq $argsHash) {
+    if (defined $prevEval && $prevEval->hash eq $argsHash && !$dryRun) {
         print STDERR "  jobset is unchanged, skipping\n";
         txn_do($db, sub {
             $jobset->update({ lastcheckedtime => time, fetcherrormsg => undef });
@@ -137,6 +138,18 @@ sub checkJobsetWrapped {
     my ($jobs, $nixExprInput) = evalJobs($inputInfo, $exprType, $jobset->nixexprinput, $jobset->nixexprpath);
     my $evalStop = time;
 
+    if ($dryRun) {
+        foreach my $name (keys %{$jobs}) {
+            my $job = $jobs->{$name};
+            if (defined $job->{drvPath}) {
+                print STDERR "good job $name: $job->{drvPath}\n";
+            } else {
+                print STDERR "failed job $name: $job->{error}\n";
+            }
+        }
+        return;
+    }
+
     $jobs->{$_}->{jobName} = $_ for keys %{$jobs};
 
     my $jobOutPathMap = {};
@@ -268,7 +281,7 @@ sub checkJobset {
         txn_do($db, sub {
             $jobset->update({lastcheckedtime => time});
             setJobsetError($jobset, $msg);
-        });
+        }) if !$dryRun;
         $failed = 1;
     }
 
@@ -280,8 +293,9 @@ sub checkJobset {
             my $new = $jobset->get_from_storage();
             $jobset->update({ triggertime => undef })
                 if $new->triggertime == $triggerTime;
-        });
+        }) if !$dryRun;
     }
+
     return $failed;
 }