From 1609edd4a8eb6303b0b78b544c829d6f8f5ae4ce Mon Sep 17 00:00:00 2001
From: Matt John <matthew@dockstudios.co.uk>
Date: Sun, 12 Jan 2020 15:29:04 +0000
Subject: [PATCH] Fix bug where formatted arguments are passed to self._warn,
 which only accepts a single string (#371)