Set shell options explicitly, as deps_check failure was being ignored.

Sub-shells don't inherit shell options by default.

tools/ci/build_prep

@@ -1,6 +1,7 @@
 #!/bin/bash
 
-set -x
+set -exo pipefail
+
 git submodule sync --recursive
 git submodule update --init --recursive
 # Ensure none of the dependency information has changed

tools/ci/env_setup

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -eo pipefail
+
 echo '
 # Added by circleci:
 export GOPATH=~/go

tools/ci/post_check

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -eo pipefail
+
 [ -f /tmp/test_flags/errors ] || exit 0
 echo "ERROR: the following actions failed:"
 echo "===================================="

tools/ci/run

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set +e
+set -o pipefail
 
 mkdir -p /tmp/test_flags || exit 1