From cc55e4e5a933176dbbc6bc9d5dd4dec6bda6fc49 Mon Sep 17 00:00:00 2001
From: MarcoFalke <falke.marco@gmail.com>
Date: Mon, 16 Nov 2020 07:59:39 +0100
Subject: [PATCH] Merge #20390: CI/Cirrus: Skip merge_base step for non-PRs

20e491ddcb2617472c15294067768e8ce122499a CI/Cirrus: Skip merge_base step for non-PRs (Luke Dashjr)

Pull request description:

  CIRRUS_BASE_BRANCH is a PR-specific variable and undocumented on non-PR builds.
  In practice (at the moment), it seems to be HEAD, which in private repositories can be pretty much anything, causing CI to fail if it can't be cleanly merged.

  By checking CIRRUS_PR first, we can reliably do CI builds of branches outside PRs.

ACKs for top commit:
  MarcoFalke:
    review ACK 20e491ddcb2617472c15294067768e8ce122499a

Tree-SHA512: 9fd8db2e19a3145f7dccfca107631b20df8c94d385f624e2bcef2fa18e38bf3e23c6c68fc8241decedbf1413bf69ca572cff75e1ccf82c09ac50443001ec5ae5
---
 .cirrus.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.cirrus.yml b/.cirrus.yml
index 7c5f94092e..23b298ef6c 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -29,6 +29,7 @@ global_task_template: &GLOBAL_TASK_TEMPLATE
   depends_releases_cache:
     folder: "/tmp/cirrus-ci-build/releases"
   merge_base_script:
+    - if [ "$CIRRUS_PR" = "" ]; then exit 0; fi
     - bash -c "$PACKAGE_MANAGER_INSTALL git"
     - git fetch $CIRRUS_REPO_CLONE_URL $CIRRUS_BASE_BRANCH
     - git config --global user.email "ci@ci.ci"