RoleRequirement - Include stderr in the error message (#66006)

* RoleRequirement - Include stderr in the error message if there's a non-0 return code

* Don't try to concatenate str and bytes

Co-Authored-By: Sam Doran <sdoran@redhat.com>

changelogs/fragments/66006-RoleRequirement-include-stderr-error-msg.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - RoleRequirement - include stderr in the error message if a scm command fails (https://github.com/ansible/ansible/issues/41336)

lib/ansible/playbook/role/requirement.py

@@ -145,11 +145,11 @@ class RoleRequirement(RoleDefinition):
             except Exception as e:
                 ran = " ".join(cmd)
                 display.debug("ran %s:" % ran)
-                display.debug("\tstdout: " + stdout)
-                display.debug("\tstderr: " + stderr)
+                display.debug("\tstdout: " + to_text(stdout))
+                display.debug("\tstderr: " + to_text(stderr))
                 raise AnsibleError("when executing %s: %s" % (ran, to_native(e)))
             if popen.returncode != 0:
-                raise AnsibleError("- command %s failed in directory %s (rc=%s)" % (' '.join(cmd), tempdir, popen.returncode))
+                raise AnsibleError("- command %s failed in directory %s (rc=%s) - %s" % (' '.join(cmd), tempdir, popen.returncode, to_native(stderr)))
 
         if scm not in ['hg', 'git']:
             raise AnsibleError("- scm %s is not currently supported" % scm)