From b563439274a402e33541f5695b1bfd4ac1085638 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Sat, 23 Nov 2019 16:00:39 +0900
Subject: [PATCH] Show include directive differences only when under git

When building from tarballs, the source directory is not a git
repository.
---
 common.mk | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/common.mk b/common.mk
index 018280b4d8..dceeeabd48 100644
--- a/common.mk
+++ b/common.mk
@@ -723,7 +723,9 @@ clean-spec: PHONY
 
 check: main test test-tool test-all test-spec
 	$(ECHO) check succeeded
-	- $(GIT) --no-pager -C "$(srcdir)" log --format=oneline -G "^ *# *include" origin/master..HEAD
+	-$(Q) if [ x"$(GIT)" != x ] && $(CHDIR) "$(srcdir)" && $(GIT) rev-parse > /dev/null 2>&1; then \
+	  set -x; $(GIT) --no-pager log --format=oneline -G "^ *# *include" origin/master..HEAD; \
+	fi
 check-ruby: test test-ruby
 
 fake: $(CROSS_COMPILING)-fake