From c7fd64e0c85f0e22ba8b2afbb286836f677e554a Mon Sep 17 00:00:00 2001
From: jack1142 <6032823+jack1142@users.noreply.github.com>
Date: Mon, 20 Jan 2020 23:09:55 +0100
Subject: [PATCH] [Downloader] Improve `InstalledCog` converter's error message
 (#3409)

* Update converters.py

* Create 3409.misc.rst
---
 changelog.d/downloader/3409.misc.rst | 1 +
 redbot/cogs/downloader/converters.py | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/downloader/3409.misc.rst

diff --git a/changelog.d/downloader/3409.misc.rst b/changelog.d/downloader/3409.misc.rst
new file mode 100644
index 000000000..d2bc0e365
--- /dev/null
+++ b/changelog.d/downloader/3409.misc.rst
@@ -0,0 +1 @@
+Improve error message when user passes cog that isn't installed to a command that only accepts installed cogs.
diff --git a/redbot/cogs/downloader/converters.py b/redbot/cogs/downloader/converters.py
index 5b7357579..483918d4a 100644
--- a/redbot/cogs/downloader/converters.py
+++ b/redbot/cogs/downloader/converters.py
@@ -15,6 +15,8 @@ class InstalledCog(InstalledModule):
 
         cog = discord.utils.get(await downloader.installed_cogs(), name=arg)
         if cog is None:
-            raise commands.BadArgument(_("That cog is not installed"))
+            raise commands.BadArgument(
+                _("Cog `{cog_name}` is not installed.").format(cog_name=arg)
+            )
 
         return cog