From d61f7d67bd3bb2030af3f3c690b8ff7c7b65e0d3 Mon Sep 17 00:00:00 2001
From: Gert Hengeveld <info@ghengeveld.nl>
Date: Mon, 2 Nov 2020 20:19:32 +0100
Subject: [PATCH] Handle ambiguous refname warning.

---
 bin/git/git.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/git/git.js b/bin/git/git.js
index 71e6ed090..70f8263c4 100644
--- a/bin/git/git.js
+++ b/bin/git/git.js
@@ -398,7 +398,7 @@ export async function getUpdateMessage() {
  */
 export async function findMergeBase(headRef, baseRef) {
   const result = await execGitCommand(`git merge-base --all ${headRef} ${baseRef}`);
-  const mergeBases = result.split(EOL).filter(Boolean);
+  const mergeBases = result.split(EOL).filter(line => line && !line.startsWith('warning: '));
   if (mergeBases.length === 0) return undefined;
   if (mergeBases.length === 1) return mergeBases[0];