Merge branch 'sg/travis-specific-cc'

The travis CI scripts have been corrected to build Git with the
compiler(s) of our choice.

* sg/travis-specific-cc:
  travis-ci: build with the right compiler
  travis-ci: switch to Xcode 10.1 macOS image
  travis-ci: don't be '--quiet' when running the tests
  .gitignore: ignore external debug symbols from GCC on macOS

.gitignore

@@ -229,3 +229,4 @@
 *.pdb
 /Debug/
 /Release/
+*.dSYM

.travis.yml

@@ -8,6 +8,8 @@ os:
   - linux
   - osx
+osx_image: xcode10.1
+
 compiler:
   - clang
   - gcc

ci/install-dependencies.sh

@@ -40,6 +40,11 @@ osx-clang|osx-gcc)
 	brew install git-lfs gettext
 	brew link --force gettext
 	brew install caskroom/cask/perforce
+	case "$jobname" in
+	osx-gcc)
+		brew link gcc@8
+		;;
+	esac
 	;;
 StaticAnalysis)
 	sudo apt-get -q update

ci/lib-travisci.sh

@@ -99,12 +99,14 @@ export DEFAULT_TEST_TARGET=prove
 export GIT_PROVE_OPTS="--timer --jobs 3 --state=failed,slow,save"
 export GIT_TEST_OPTS="--verbose-log -x --immediate"
 export GIT_TEST_CLONE_2GB=YesPlease
-if [ "$jobname" = linux-gcc ]; then
-	export CC=gcc-8
-fi
 case "$jobname" in
 linux-clang|linux-gcc)
+	if [ "$jobname" = linux-gcc ]
+	then
+		export CC=gcc-8
+	fi
+
 	export GIT_TEST_HTTPD=YesPlease
 	# The Linux build installs the defined dependency versions below.
@@ -118,6 +120,11 @@ linux-clang|linux-gcc)
 	export PATH="$GIT_LFS_PATH:$P4_PATH:$PATH"
 	;;
 osx-clang|osx-gcc)
+	if [ "$jobname" = osx-gcc ]
+	then
+		export CC=gcc-8
+	fi
+
 	# t9810 occasionally fails on Travis CI OS X
 	# t9816 occasionally fails with "TAP out of sequence errors" on
 	# Travis CI OS X
@@ -127,3 +134,5 @@ GIT_TEST_GETTEXT_POISON)
 	export GIT_TEST_GETTEXT_POISON=YesPlease
 	;;
 esac
+
+export MAKEFLAGS="CC=${CC:-cc}"

ci/run-build-and-tests.sh

@@ -8,7 +8,7 @@
 ln -s "$cache_dir/.prove" t/.prove
 make --jobs=2
-make --quiet test
+make test
 if test "$jobname" = "linux-gcc"
 then
 	export GIT_TEST_SPLIT_INDEX=yes
@@ -17,7 +17,7 @@ then
 	export GIT_TEST_OE_DELTA_SIZE=5
 	export GIT_TEST_COMMIT_GRAPH=1
 	export GIT_TEST_MULTI_PACK_INDEX=1
-	make --quiet test
+	make test
 fi
 check_unignored_build_artifacts

ci/run-linux32-build.sh

@@ -56,5 +56,5 @@ linux32 --32bit i386 su -m -l $CI_USER -c '
 	cd /usr/src/git
 	test -n "$cache_dir" && ln -s "$cache_dir/.prove" t/.prove
 	make --jobs=2
-	make --quiet test
+	make test
 '