Error [13] in deploying App Engine Application using Jenkins and gcloud

Question

I am trying to deploy a mediawiki application to app engine using Jenkins as described in Google's push to deploy method https://cloud.google.com/tools/cloud-repositories/docs/push-to-deploy.

I am deploying mediawiki based on the same configurations here: https://github.com/tyolab/mediawiki-on-gae.

Some times I deploy the app and it is a success, but many times it fails with the following error:

Updating module [default].../

Updating module [default]...-

Updating module [default]...\

Updating module [default]...|

Updating module [default]...failed.

ERROR: (gcloud.preview.app.deploy) Error Response: [13]

Build step 'Execute shell' marked build as failure

Finished: FAILURE

There is no specific pattern, and the error is not descriptive, but I noticed the following:

• If I deploy to a new staging container and a new version it usually works the first time, but later on it doesn't

• I suspect it has something to do with static resources, as if I add some more static resources files "The ones commented out in the app.yaml sample below" the deployment fails

• I suspected it is related to the issue described here, but the set +e solution didn't work for me How/When does Execute Shell mark a build as failure in Jenkins?

This is the build command that I use

set +e
gcloud --project=projectid preview app deploy app.yaml --version=3 --promote --bucket gs://projectstagingbucket --force

And here is a sample of the app.yaml file:

handlers:

# Static pages
#- url: /(.*\.(htm|html|css|js))
#  static_files: \1
#  upload: .*\.(htm|html|css|js)
#  application_readable: true

# Serve images as static resources.
#- url: /resources/(.*\.(ico|jpg|jpeg|png|xcf|gif|woff|woff2|cur|ttf|otf|eot|svg))
#  static_files: resources/\1
#  upload: /resources/.*\.(ico|jpg|jpeg|png|xcf|gif|woff|woff2|cur|ttf|otf|eot|svg)
#  application_readable: true

  # Serve images as static resources.
#- url: /vendor/(.*\.(ico|jpg|jpeg|png|xcf|gif|woff|woff2|cur|ttf|otf|eot|svg))
#  static_files: vendor/\1
#  upload: vendor/.*\.(ico|jpg|jpeg|png|xcf|gif|woff2|cur|woff|ttf|otf|eot|svg)
#  application_readable: true

  # Serve images as static resources.
#- url: /skins/(.*\.(ico|jpg|jpeg|png|xcf|woff2|gif|woff|cur|ttf|otf|eot|svg))
#  static_files: skins/\1
#  upload: skins/.*\.(ico|jpg|jpeg|png|xcf|gif|woff2|woff|cur|ttf|otf|eot|svg)
#  application_readable: true
  
- url: /favicon.ico
  static_files: favicon.ico
  upload: favicon.ico
  application_readable: true

#- url: /(.+\.(ico|jpg|jpeg|png|gif|woff|ttf|otf|eot|svg))
#  static_files: \1
#  upload: .+\.(ico|jpg|jpeg|png|gif|woff|ttf|otf|eot|svg)
#  application_readable: true
  
- url: /robots.txt
  static_files: robots.txt
  upload: robots.txt
  application_readable: true

# Misc files.
- url: /(.+\.(xsd|txt|sql|))
  static_files: \1
  upload: .+\.(xsd|txt|sql)
  application_readable: true
  
# Serve MediaWiki installation scripts
# can be removed after installation
#- url: /mw-config/
#  script: mw-config/index.php
#  secure: always
  
# Serve mw-config images as static resources.
#- url: /mw-config/images/(.*\.(ico|jpg|jpeg|png|gif|woff|ttf|otf|eot|svg))
#  static_files: mw-config/images/\1
#  upload: mw-config/images/.*\.(ico|jpg|jpeg|png|gif|woff|ttf|otf|eot|svg)
#  application_readable: true
  
# Serve images from Google Cloud Storage 
- url: /images/(.*\.(ico|jpg|jpeg|xcf|png|gif|woff|woff2|cur|ttf|otf|eot|svg))
  script: extensions/CloudStorage/GoogleCloudStorageFileServe.php
  secure: optional
  
# Serve php5 scripts.
- url: /(.+\.php5)
  script: \1

# Serve php scripts.
- url: /(.+\.php)
  script: \1
 
# 
- url: (.*)/(.*)
  script: index.php
  secure: optional
  
# redirect root to wiki path
- url: /?
  script: index.php
  secure: optional
  
# 404 
- url: /(.*)
#  script: /wiki/Special:Error404
#  
#- url: /wiki/Special:Error404
  script: index.php

Thanks in advance.