Ignore build step

[Neo-Oli]

Can you tell me what kind of commands are available in the ignore build step option? We want to filter deploys based on branch name.

# Branch name is 'feature/test-featurename'
echo "$VERCEL_GITHUB_COMMIT_REF"| grep -v test

But this will cause it to always skip building.
I tested it with the following two commands as well

sh -c 'exit 1'
sh -c 'exit 0'

But both cause the build to continue, so I am a bit confused.

[styfle]

Any command should work.

There is a similar discussion here: #5142

[hoomanaskari]

Just a quick question on this while you are working on the fix;

The Vercel documentation says:
"To run a bash script in the "Ignored Build Step", you need to set the following in the field: sh script.sh. Do notice the file should exist in your repository."

By sh script.sh you mean a file named sh script.sh (containing a space in the name) or a folder named sh with a file named script.sh inside the root directory of my react app? Thanks in advance.

[ys-chung]

@hoomanaskari A file named script.sh in the root of the repo.

[hoomanaskari]

Thank you very much. I can also confirm that the following code is not working for me:

#!/bin/bash

# Retrieve branch name
branch=$(git branch --show-current)

if [ "$branch" == "master" ]; then
  # Proceed with build
    exit 1;
else
  # Don't build
  exit 0;
fi

But I suppose a fix is on the way.

[paulogdm]

Hello everyone!

We've discussed this matter internally and we will release improvements to this command soon. For now, I will pull the guide from our knowledge DB. You can speak a big update before the end of the year.

[hunterwilhelm]

For anyone still trying to use git branch --show-current in the Ignore Build Step, it doesn't change between source branches. Instead, use $VERCEL_GIT_COMMIT_REF. Read the tutorial from the answer & All System Variables Documentation

[paulogdm]

Hello!

With the release of our new Environment Variables UI, I have added a couple of examples to our KB article: https://vercel.com/knowledge/how-do-i-use-the-ignored-build-step-field-on-vercel

Feedbacks are welcome.

[svobik7]

@paulogdm thank you, it is working now.

[dborstelmann]

@paulogdm Working for me as well, thanks for the quick turnaround.

[bfabio]

@paulogdm We are using the external script approach, but we want to skip the gh-pages branch, which is automatically pushed with only the artifacts of the build. Is there a way to do it without pushing the script itself to the gh-pages branch?

Being able to use shell piping in the command would fix our issues.

[jonashaefele]

Related to the guide @paulogdm linked to more than the discussion above. Just found this after getting a bit stuck...

I set up two vercel projects from a mono-repo sort of like described in https://vercel.com/docs/git?query=monorepo

My structure is like this:

/shared
    /components
    /lib
    /...
/app-one
/app-two

app-one and app-two share a design system and a few config files from shared linked with yarn workspaces and a little tsconfig magic. That all works perfectly.

But it took me ages to realise that the ignore build step command is running in the root folder of the individual deployment, and not the root of the repo. It's all linked and discoverable. So all totally my fault.

But might be worth adding an example at https://vercel.com/docs/git?query=monorepo#ignoring-the-build-step or in the guide mentioned above at https://vercel.com/knowledge/how-do-i-use-the-ignored-build-step-field-on-vercel#with-folders-and-workspaces

Ignore commands in my case were:

For app-one: git diff --quiet HEAD^..HEAD -- .. ':!app-two'
For app-two: git diff --quiet HEAD^..HEAD -- .. ':!app-one'

It's literally just those two little dots that made it work. Took me a while to get that I need to go one level up, from the app root to the repo root. So it's -- .. ':!app-two' not -- . ':!app-two'

This way both changes to the shared design system and the app that's getting deployed let the deployment continue, but changes to the unrelated app abort the deployment.

[gregg-cbs]

Oh my goodness! I gave up on this and then about 3 months later started looking into it... the .. is the saving grace.

Why on earth vercel do you set the default path for this as the root directory. We are talking about repository level routes here and you start it inside the project root. Im sure many people dont understand this.

You need to update your docs to make this clear because without Neo i would never have known.
So essentially most people would want ./

[maltesa]

I'm trying to make this work, as I want to deploy when there are changes between the last deployment and the current HEAD:

git diff $VERCEL_GIT_PREVIOUS_SHA HEAD --quiet ./app1

But that fails with a git error (runs fine on my local machine, though):
fatal: bad object b0eae4da9dc8c129fdda5cb06d2bf616f3b6c623 exit code 128

I don't quite get why the following makes sense. What happens if I push multiple commits, but the last one did not change anything in ./app1? In that case, no build would be triggered, right?

git diff HEAD^ HEAD --quiet ./app1