From 2227721dac8ece70521fb7551d6001a03ed9bc14 Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Thu, 2 Sep 2021 10:09:09 -0400
Subject: [PATCH] Only set event if entry still exists

---
 piker/_cacheables.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/piker/_cacheables.py b/piker/_cacheables.py
index 87b700f5..7ffa29a0 100644
--- a/piker/_cacheables.py
+++ b/piker/_cacheables.py
@@ -174,8 +174,10 @@ async def maybe_open_ctx(
                 log.warning(f'De-allocating resource for {key}')
 
                 # terminate mngr nursery
-                _, no_more_users = cache.resources[ctx_key]
-                no_more_users.set()
+                entry = cache.resources.get(ctx_key)
+                if entry:
+                    _, no_more_users = entry
+                    no_more_users.set()
 
 
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