[Python-checkins] [3.8] Pin test runner to Ubuntu 18 to un-break CI (GH-24715) (GH-24717)

[miss-islington]

https://github.com/python/cpython/commit/9c6c5da55f4b9f4e5dde33d10adaf3d7ee824c11
commit: 9c6c5da55f4b9f4e5dde33d10adaf3d7ee824c11
branch: 3.8
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2021-03-03T01:56:41-08:00
summary:

[3.8] Pin test runner to Ubuntu 18 to un-break CI (GH-24715) (GH-24717)



(cherry picked from commit 94894dd45e4bad6efb27eac4497b24cdc18b3e2d)


Co-authored-by: Brandt Bucher <brandt at python.org>

Automerge-Triggered-By: GH:tiran

files:
M .github/workflows/build.yml

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 669c541dd4f49..5822428e34a86 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -114,7 +114,7 @@ jobs:
 
   build_ubuntu:
     name: 'Ubuntu'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-18.04
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     env: