How to fix ERROR: Couldn't find any revision to build. Verify the repository and branch configuration in Git

The most common cause is GitHub's default branch name change from master to main. Update your Jenkins job configuration:

For Freestyle Jobs:
1. Go to your job configuration
2. Navigate to Source Code Management > Git
3. Find Branches to build > Branch Specifier
4. Change */master to */main

For Pipeline Jobs:
Update your Jenkinsfile or pipeline script:

// Old configuration (fails with new repos)
git branch: 'master', url: 'https://github.com/your-org/your-repo.git'

// Updated configuration
git branch: 'main', url: 'https://github.com/your-org/your-repo.git'

Or using checkout SCM:

checkout([
    $class: 'GitSCM',
    branches: [[name: '*/main']],
    userRemoteConfigs: [[url: 'https://github.com/your-org/your-repo.git']]
])

Tip: If unsure of your branch name, check your repository directly or leave the Branch Specifier blank to build any available branch.

Sometimes wildcard patterns like */main cause issues. Use the explicit refs/heads syntax:

Change the Branch Specifier to:

refs/heads/main

Or for remote tracking:

refs/remotes/origin/main

In Pipeline scripts:

checkout([
    $class: 'GitSCM',
    branches: [[name: 'refs/heads/main']],
    userRemoteConfigs: [[
        url: 'https://github.com/your-org/your-repo.git',
        credentialsId: 'github-credentials'
    ]]
])

This explicit syntax avoids ambiguity when multiple refs could match a pattern.

If your branch specifier uses variables like ${gitlabSourceBranch} or ${sha1}, these are undefined during manual builds:

For GitLab webhooks with ${gitlabSourceBranch}:
1. Check This project is parameterized in job configuration
2. Add String Parameter:
- Name: gitlabSourceBranch
- Default Value: main (or your default branch)

For GitHub webhooks with ${sha1}:
1. Check This project is parameterized
2. Add String Parameter:
- Name: sha1
- Default Value: main

In Pipeline scripts, handle undefined variables:

def branchName = env.gitlabSourceBranch ?: 'main'
checkout([
    $class: 'GitSCM',
    branches: [[name: branchName]],
    userRemoteConfigs: [[url: env.GIT_URL]]
])

When triggered by webhook, the variable will be populated. When triggered manually, the default value is used.

Jenkins showing "Seen 0 remote branches" often indicates credential issues:

Test credentials manually:
1. Go to Manage Jenkins > Credentials
2. Find your Git credentials and note the ID
3. Use Jenkins Script Console (Manage Jenkins > Script Console):

def creds = com.cloudbees.plugins.credentials.CredentialsProvider.lookupCredentials(
    com.cloudbees.plugins.credentials.common.StandardUsernameCredentials.class,
    Jenkins.instance,
    null,
    null
)
creds.each { println it.id + ": " + it.username }

In your job configuration:
1. Under Source Code Management > Git > Repositories
2. Expand Advanced
3. Verify Credentials dropdown shows your credential

For Pipeline, explicitly specify credentialsId:

checkout([
    $class: 'GitSCM',
    branches: [[name: '*/main']],
    userRemoteConfigs: [[
        url: 'https://github.com/your-org/your-repo.git',
        credentialsId: 'your-credential-id'
    ]]
])

Common credential issues:
- SSH key without passphrase required for automated builds
- Personal Access Token expired or revoked
- GitHub App token doesn't have repository permission
- Username/password auth blocked (GitHub deprecated this in 2021)

Copy-pasting branch names can introduce invisible Unicode characters that break Git lookups:

Symptoms:
- Branch specifier looks correct in the UI
- Console log shows the expected branch name
- Git still can't find the revision

Fix:
1. Go to job configuration
2. In Branch Specifier field, select all text and delete it
3. Type the branch name manually - do not paste

Verify in console output:

# If you see something like this with extra characters:
> git rev-parse "​main^{commit}"  # Hidden zero-width space before 'main'

# It should look like this:
> git rev-parse "main^{commit}"

Pipeline script fix:

// Ensure branch name is clean
def branch = "main".trim()
checkout([
    $class: 'GitSCM',
    branches: [[name: branch]],
    userRemoteConfigs: [[url: env.GIT_URL]]
])

If you're not sure which branch to specify, leaving it blank tells Jenkins to build any available branch:

For Freestyle jobs:
1. Go to Source Code Management > Git
2. Find Branches to build > Branch Specifier
3. Remove all text (leave completely empty)

Jenkins will now build whatever branch is available, which is useful for debugging whether the issue is branch-specific.

For webhook-triggered builds:
Leaving it blank means Jenkins will build whichever branch triggered the webhook, which is often the desired behavior.

Once you've confirmed builds work, specify the branch:

*/main

Or use a pattern to build feature branches:

*/feature-*

The refspec determines which refs Jenkins fetches. Misconfigured refspec causes "cannot find revision" errors:

Default refspec:

+refs/heads/*:refs/remotes/origin/*

For pull request builds (GitHub):

+refs/pull/*:refs/remotes/origin/pr/*

For merge requests (GitLab):

+refs/merge-requests/*/head:refs/remotes/origin/merge-requests/*

Configure in Freestyle job:
1. Source Code Management > Git
2. Click Advanced under Repositories
3. Set Refspec field

Pipeline configuration:

checkout([
    $class: 'GitSCM',
    branches: [[name: 'refs/remotes/origin/pr/${ghprbPullId}/merge']],
    userRemoteConfigs: [[
        url: 'https://github.com/your-org/your-repo.git',
        refspec: '+refs/pull/*:refs/remotes/origin/pr/*',
        credentialsId: 'github-credentials'
    ]]
])

Multiple refspecs:

refspec: '+refs/heads/*:refs/remotes/origin/* +refs/pull/*:refs/remotes/origin/pr/*'

Shallow clones may not include the commit SHA you're trying to build:

Symptoms:
- Building specific commit SHAs fails
- "fatal: reference is not a tree" errors
- Works for HEAD but not for older commits

Disable shallow clone in Freestyle jobs:
1. Source Code Management > Git
2. Click Additional Behaviours > Add
3. Select Advanced clone behaviours
4. Uncheck Shallow clone or set Shallow clone depth to 0

Pipeline configuration:

checkout([
    $class: 'GitSCM',
    branches: [[name: '*/main']],
    extensions: [
        [$class: 'CloneOption',
         depth: 0,           // Full clone
         noTags: false,
         shallow: false]
    ],
    userRemoteConfigs: [[url: 'https://github.com/your-org/your-repo.git']]
])

For commit SHA builds:

// Fetch enough history to include the target commit
checkout([
    $class: 'GitSCM',
    branches: [[name: '${COMMIT_SHA}']],
    extensions: [
        [$class: 'CloneOption', depth: 100, shallow: true]
    ],
    userRemoteConfigs: [[url: env.GIT_URL]]
])

URL format issues can prevent Jenkins from connecting to the repository:

Check these common URL issues:

1. Missing .git suffix (sometimes required):

# Try with .git
https://github.com/your-org/your-repo.git

# Instead of
https://github.com/your-org/your-repo

2. SSH vs HTTPS mismatch with credentials:

// For SSH credentials, use SSH URL:
[email protected]:your-org/your-repo.git

// For username/token credentials, use HTTPS:
https://github.com/your-org/your-repo.git

3. Test URL accessibility from Jenkins agent:

# SSH with a pipeline step
sh 'ssh -T [email protected] || true'

# HTTPS
sh 'git ls-remote https://github.com/your-org/your-repo.git'

4. For private repositories, include credentials:

checkout([
    $class: 'GitSCM',
    branches: [[name: '*/main']],
    userRemoteConfigs: [[
        url: 'https://github.com/your-org/private-repo.git',
        credentialsId: 'github-pat'
    ]]
])