https://bugs.gentoo.org/964608
(Tangentially: https://bugs.debian.org/1118288)
https://lore.kernel.org/git/4e2952e512afc780b621d2c153b3e6e4eb7ed89a.camel@xry111.site/
--- a/t/t7528-signed-commit-ssh.sh
+++ b/t/t7528-signed-commit-ssh.sh
@@ -82,7 +82,7 @@ test_expect_success GPGSSH 'create signed commits' '
 test_expect_success GPGSSH 'sign commits using literal public keys with ssh-agent' '
 	test_when_finished "test_unconfig commit.gpgsign" &&
 	test_config gpg.format ssh &&
-	eval $(ssh-agent) &&
+	eval $(ssh-agent -T || ssh-agent) &&
 	test_when_finished "kill ${SSH_AGENT_PID}" &&
 	test_when_finished "test_unconfig user.signingkey" &&
 	mkdir tmpdir &&