Better error messages on the CI

This makes it so that when a ci target fails, we don't get red herring
error messages about .ok files not existing.

Since this requires bash, we make a helper script that invokes bash, so
as to not depend on bash in general.

2 files changed, 9 insertions, 3 deletions

diff --git a/Makefile.ci b/Makefile.ci
index 1b09905cc7..a5b3b1491d 100644
--- a/Makefile.ci
+++ b/Makefile.ci
@@ -24,9 +24,7 @@ CI_TARGETS=ci-all \
 
 # Generic rule, we use make to easy travis integraton with mixed rules
 $(CI_TARGETS): ci-%:
-	rm -f ci-$*.ok
-	+(./dev/ci/ci-$*.sh 2>&1 && touch ci-$*.ok) | tee time-of-build.log
+	+./dev/ci/ci-pipe-tee.sh ./dev/ci/ci-$*.sh time-of-build.log
 	echo 'Aggregating timing log...' && echo -en 'travis_fold:start:coq.test.timing\\r'
 	python ./tools/make-one-time-file.py time-of-build.log
 	echo -en 'travis_fold:end:coq.test.timing\\r'
-	rm ci-$*.ok # must not be -f; we're checking to see that it exists
diff --git a/dev/ci/ci-pipe-tee.sh b/dev/ci/ci-pipe-tee.sh
new file mode 100755
index 0000000000..7b1ccddf23
--- /dev/null
+++ b/dev/ci/ci-pipe-tee.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+# Use this script to preserve the exit code of $1 when piping it to
+# `tee $2`.  We have a separate script, because this only works in
+# bash, which we don't require project-wide.
+
+"$1" 2>&1 | tee "$2"
+exit ${PIPESTATUS[0]}