troubleshooting: handle nil from wnohang flag

Author: dcaddell

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    kubernetes_template_rendering (0.2.1.pre.dc.5)
+    kubernetes_template_rendering (0.2.1.pre.dc.6)
       activesupport
       invoca-utils
       jsonnet

lib/kubernetes_template_rendering/template_directory_renderer.rb

@@ -68,13 +68,16 @@ def read_definitions(path)
     def wait_if_max_forked(child_pids)
       while child_pids.size >= MAX_FORKED_PROCESSES
         begin
-          Process.waitpid # this is a race condition because 1 or more processes could exit before we get here
+          pid, exit_status = Process.waitpid2 # this is a race condition because 1 or more processes could exit before we get here
+          exit_status.success? or raise "Child process #{pid} failed"
         rescue SystemCallError # this will happen if they all exited before we called waitpid
         end
         child_pids.delete_if do |pid|
           begin
             _, exit_status = Process.waitpid2(pid, Process::WNOHANG)
-            exit_status.success? or raise "Child process #{pid} failed"
+            if exit_status
+              exit_status.success? or raise "Child process #{pid} failed"
+            end
           rescue Errno::ECHILD # No child processes
             true
           end

lib/kubernetes_template_rendering/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module KubernetesTemplateRendering
-  VERSION = "0.2.1.pre.dc.5"
+  VERSION = "0.2.1.pre.dc.6"
 end