Update travis.yml with set +e

.travis.yml

@@ -11,12 +11,7 @@ cache:
   - $HOME/.cache/pip
   - $HOME/.ccache
 
-# we set +e to re-instate the error-tolerant state. The problem is Travis is broken on Mac OS
-# builds right now due to Issue 6307 (https://github.com/travis-ci/travis-ci/issues/6307)
-# and fails at the end of a successful build. This will allow the build to recover even if
-# a non-zero status code is encountered.
 before_install:
-  - set +e
   - source build_tools/travis/before_install.sh
 env:
   global:
@@ -90,8 +85,14 @@ matrix:
 install: source build_tools/travis/install.sh
 before_script: bash build_tools/travis/before_script.sh
 script: bash build_tools/travis/test_script.sh
+
+# we set +e to re-instate the error-tolerant state. The problem is Travis is broken on Mac OS
+# builds right now due to Issue 6307 (https://github.com/travis-ci/travis-ci/issues/6307)
+# and fails at the end of a successful build. This will allow the build to recover even if
+# a non-zero status code is encountered.
 after_success:
-  - source build_tools/travis/after_success.sh # || "shell_session_update failed"
+  - set +e
+  - source build_tools/travis/after_success.sh || echo "shell_session_update failed"
   # Build the wheels every time so we can debug
   - bash build_tools/travis/build_wheels.sh
   - ls dist/