Run lint:all tasks in forks

lib/tasks/lint.rake

@@ -20,7 +20,6 @@ unless Rails.env.production?
     desc "GitLab | lint | Run several lint checks"
     task :all do
       status = 0
-      original_stdout = $stdout
 
       %w[
         config_lint
@@ -30,19 +29,41 @@ unless Rails.env.production?
         gettext:lint
         lint:static_verification
       ].each do |task|
-        begin
-          $stdout = StringIO.new
-          Rake::Task[task].invoke
-        rescue RuntimeError, SystemExit => ex
-          raise ex if ex.is_a?(RuntimeError) && task != 'haml_lint'
-          original_stdout << $stdout.string
-          status = 1
-        ensure
-          $stdout = original_stdout
+        pid = Process.fork do
+          rd, wr = IO.pipe
+          stdout = $stdout.dup
+          stderr = $stderr.dup
+          $stdout.reopen(wr)
+          $stderr.reopen(wr)
+
+          begin
+            begin
+              Rake::Task[task].invoke
+            rescue RuntimeError # The haml_lint tasks raise a RuntimeError
+              exit(1)
+            end
+          rescue SystemExit => ex
+            msg = "*** Rake task #{task} failed with the following error(s):"
+            raise ex
+          ensure
+            $stdout.reopen(stdout)
+            $stderr.reopen(stderr)
+            wr.close
+
+            if msg
+              warn "\n#{msg}\n\n"
+              IO.copy_stream(rd, $stderr)
+            else
+              IO.copy_stream(rd, $stdout)
+            end
+          end
         end
+
+        Process.waitpid(pid)
+        status += $?.exitstatus
       end
 
-      exit status
+      exit(status)
     end
   end
 end

scripts/static-analysis

@@ -7,7 +7,7 @@ require_relative '../lib/gitlab/popen/runner'
 def emit_warnings(static_analysis)
   static_analysis.warned_results.each do |result|
     puts
-    puts "**** #{result.cmd.join(' ')} had the following warnings:"
+    puts "**** #{result.cmd.join(' ')} had the following warning(s):"
     puts
     puts result.stderr
     puts
@@ -17,7 +17,7 @@ end
 def emit_errors(static_analysis)
   static_analysis.failed_results.each do |result|
     puts
-    puts "**** #{result.cmd.join(' ')} failed with the following error:"
+    puts "**** #{result.cmd.join(' ')} failed with the following error(s):"
     puts
     puts result.stdout
     puts result.stderr