Report silent build command failures

Author: ChiragAgg5k

src/Executor/Runner/Docker.php

@@ -386,7 +386,12 @@ public function createRuntime(
                     );
 
                     if (!$status) {
-                        throw new ExecutorException(ExecutorException::RUNTIME_FAILED, 'Failed to create runtime: ' . $stdout);
+                        $message = \trim($stdout);
+
+                        throw new ExecutorException(
+                            ExecutorException::RUNTIME_FAILED,
+                            $message === '' ? 'Build command failed.' : $message
+                        );
                     }
 
                     if ($version === 'v2') {
@@ -545,14 +550,14 @@ private function getBuildCommands(string $command, string $version): array
             return [
                 'sh',
                 '-c',
-                'touch /var/tmp/logs.txt && (' . $command . ') >> /var/tmp/logs.txt 2>&1 && cat /var/tmp/logs.txt'
+                'touch /var/tmp/logs.txt && (' . $command . ') >> /var/tmp/logs.txt 2>&1; status=$?; cat /var/tmp/logs.txt; if [ $status -ne 0 ] && [ ! -s /var/tmp/logs.txt ]; then echo "Build command exited with code $status."; fi; exit $status'
             ];
         }
 
         return [
             'bash',
             '-c',
-            'mkdir -p /tmp/logging && touch /tmp/logging/timings.txt && touch /tmp/logging/logs.txt && script --log-out /tmp/logging/logs.txt --flush --log-timing /tmp/logging/timings.txt --return --quiet --command "' . \str_replace('"', '\"', $command) . '"'
+            'mkdir -p /tmp/logging && touch /tmp/logging/timings.txt && touch /tmp/logging/logs.txt && script --log-out /tmp/logging/logs.txt --flush --log-timing /tmp/logging/timings.txt --return --quiet --command "' . \str_replace('"', '\"', $command) . '"; status=$?; if [ $status -ne 0 ] && [ ! -s /tmp/logging/logs.txt ]; then echo "Build command exited with code $status."; fi; exit $status'
         ];
     }
 

tests/unit/Executor/Runner/DockerTest.php

@@ -44,6 +44,19 @@ public function testNoCacheLifecycleShellCommandsAreGenerated(): void
         $this->assertStringNotContainsString('build-cache-save.sh', $command);
     }
 
+    public function testBuildCommandsReportSilentNonZeroExit(): void
+    {
+        $docker = $this->createDocker();
+
+        foreach (['v2', 'v5'] as $version) {
+            $commands = $this->invokeGetBuildCommands($docker, 'exit 1', $version);
+            $command = \implode(' ', $commands);
+
+            $this->assertStringContainsString('Build command exited with code $status.', $command);
+            $this->assertStringContainsString('exit $status', $command);
+        }
+    }
+
     public function testInvalidBuildCacheKeyIsRejected(): void
     {
         $this->expectException(\Exception::class);