This process allows you to completely reproduce any Travis build job on your computer. Also, you can interrupt the process at any time and debug. Below is an example where I perfectly reproduce the results of job #191.1 on php-school/cli-menu
.

Prerequisites

• You have public repo on GitHub
• You ran at least one build on Travis
• You have Docker set up on your computer

Set up the build environment

Reference: https://docs.travis-ci.com/user/common-build-problems/

1. Make up your own temporary build ID

   BUILDID="build-$RANDOM"
   

2. View the build log, open the show more button for WORKER INFORMATION and find the INSTANCE line, paste it in here and run (replace the tag after the colon with the newest available one):

   INSTANCE="travisci/ci-garnet:packer-1512502276-986baf0"
   

3. Run the headless server

   docker run --name $BUILDID -dit $INSTANCE /sbin/init
   

4. Run the attached client

   docker exec -it $BUILDID bash -l
   

Run the job

Now you are now inside your Travis environment. Run su - travis to begin.

This step is well defined but it is more tedious and manual. You will find every command that Travis runs in the environment. To do this, look for for everything in the right column which has a tag like 0.03s.

On the left side you will see the actual commands. Run those commands, in order.

Result

Now is a good time to run the history command. You can restart the process and replay those commands to run the same test against an updated code base.

• If your repo is private: ssh-keygen -t rsa -b 4096 -C "YOUR EMAIL REGISTERED IN GITHUB" then cat ~/.ssh/id_rsa.pub and click here to add a key
• FYI: you can git pull from inside docker to load commits from your dev box before you push them to GitHub
• If you want to change the commands Travis runs then it is YOUR responsibility to figure out how that translates back into a working .travis.yml.
• I don’t know how to clean up the Docker environment, it looks complicated, maybe this leaks memory