Merge branch 'sg/travis-fixes'

Assorted updates for TravisCI integration.

* sg/travis-fixes:
  travis-ci: only print test failures if there are test results available
  travis-ci: save prove state for the 32 bit Linux build
  travis-ci: don't install default addon packages for the 32 bit Linux build
  travis-ci: fine tune the use of 'set -x' in 'ci/*' scripts

Author: gitster

.travis.yml

@@ -42,6 +42,7 @@ matrix:
     - env: jobname=Linux32
       os: linux
       compiler:
+      addons:
       services:
         - docker
       before_install:

ci/lib-travisci.sh

@@ -22,7 +22,9 @@ skip_branch_tip_with_tag () {
 }
 
 # Set 'exit on error' for all CI scripts to let the caller know that
-# something went wrong
+# something went wrong.
+# Set tracing executed commands, primarily setting environment variables
+# and installing dependencies.
 set -ex
 
 skip_branch_tip_with_tag

ci/print-test-failures.sh

@@ -5,6 +5,15 @@
 
 . ${0%/*}/lib-travisci.sh
 
+# Tracing executed commands would produce too much noise in the loop below.
+set +x
+
+if ! ls t/test-results/*.exit >/dev/null 2>/dev/null
+then
+	echo "Build job failed before the tests could have been run"
+	exit
+fi
+
 for TEST_EXIT in t/test-results/*.exit
 do
 	if [ "$(cat "$TEST_EXIT")" != "0" ]

ci/run-linux32-build.sh

@@ -6,6 +6,8 @@
 #   run-linux32-build.sh [host-user-id]
 #
 
+set -x
+
 # Update packages to the latest available versions
 linux32 --32bit i386 sh -c '
     apt update >/dev/null &&
@@ -25,6 +27,7 @@ test -z $HOST_UID || (CI_USER="ci" && useradd -u $HOST_UID $CI_USER) &&
 # Build and test
 linux32 --32bit i386 su -m -l $CI_USER -c '
     cd /usr/src/git &&
+    ln -s /tmp/travis-cache/.prove t/.prove &&
     make --jobs=2 &&
     make --quiet test
 '

ci/run-linux32-docker.sh

@@ -19,5 +19,6 @@ docker run \
 	--env GIT_TEST_OPTS \
 	--env GIT_TEST_CLONE_2GB \
 	--volume "${PWD}:/usr/src/git" \
+	--volume "${HOME}/travis-cache:/tmp/travis-cache" \
 	daald/ubuntu32:xenial \
 	/usr/src/git/ci/run-linux32-build.sh $(id -u $USER)

ci/run-windows-build.sh

@@ -69,6 +69,10 @@ esac
 
 echo "Visual Studio Team Services Build #${BUILD_ID}"
 
+# Tracing execued commands would produce too much noise in the waiting
+# loop below.
+set +x
+
 # Wait until build job finished
 STATUS=
 RESULT=
@@ -90,6 +94,7 @@ done
 # Print log
 echo ""
 echo ""
+set -x
 gfwci "action=log&buildId=$BUILD_ID" | cut -c 30-
 
 # Set exit code for TravisCI