Here a quick blog post how to update Trellis like a pro.

Requirements

Here are some requirements or basically tips before you get started

• Trellis should be in its own repo not together with Bedrock/Site
• Always make sure you’re working in a Git repo
• Make sure all your work is committed
• Use a great IDE like Visual Code to deal with merge conlficts

Trellis As Upstream Remote

Add Trellis as a remote

git remote add upstream git@github.com:roots/trellis.git

The pull the upstream changes using

 git fetch upstream

You will then see something like

git fetch upstream
remote: Counting objects: 40, done.
remote: Compressing objects: 100% (6/6), done.
remote: Total 40 (delta 24), reused 29 (delta 24), pack-reused 9
Unpacking objects: 100% (40/40), done.
From github.com:roots/trellis
   c8515b3..14cce04  master                -> upstream/master
 * [new branch]      memcached-disable-udp -> upstream/memcached-disable-udp

Once that is done rebase upstream changes into your master repository using

 git rebase upstream/master

Git Merge Conflicts

Manually fix all conflicts. I recommend Visual Code as it visually helps you to deal with it all as you see in the image below. Also read: https://help.github.com/articles/resolving-merge-conflicts-after-a-git-rebase/46 and http://tedfelix.com/software/git-conflict-resolution.html26

In Visual Studio Code you simply need to accept current change (added by upstream) or keep incoming change. And the latter you have to do for most if not all group_vars files.

Rebase Continued

Once you have fixed all conflicts you can do a

git add .
git rebase --continue

Merge Conflicts Leftovers

When I continued the rebasing I got a few more merge conflicts:

Falling back to patching base and 3-way merge...
Auto-merging group_vars/development/vault.yml
CONFLICT (content): Merge conflict in group_vars/development/vault.yml
Auto-merging Vagrantfile
Auto-merging README.md
Auto-merging CHANGELOG.md
CONFLICT (content): Merge conflict in CHANGELOG.md
error: Failed to merge in the changes.
Patch failed at 0002 first commit
The copy of the patch that failed is found in: .git/rebase-apply/patch

When you have resolved this problem, run "git rebase --continue".
If you prefer to skip this patch, run "git rebase --skip" instead.
To check out the original branch and stop rebasing, run "git rebase --abort".

So I fixed the files and overwrote changelog, README and Vagrantfile with the latest from the repo at Github. Then I rebased again and… all good!

NB This blog post is based on Swalkinshaw’s post at Roots Discourse on updating Sage