1. Non-shallow clone using pipeline DSL: 
checkout([$class: 'GitSCM', branches: [[name: branchName]], doGenerateSubmoduleConfigurations: false, extensions: [[$class: 'LocalBranch', localBranch: branchName], [$class: 'CleanBeforeCheckout'], [$class: 'CloneOption', noTags: false, reference: '', shallow: false, timeout: 10]], submoduleCfg: [], userRemoteConfigs: [[url: 'git@github.corp.xxxx.com:'+orgName+'/'+repoName+'.git']]])

2. Shallow clone using pipeline DSL : 
checkout([$class: 'GitSCM', branches: [[name: branchName]], doGenerateSubmoduleConfigurations: false, extensions: [[$class: 'LocalBranch', localBranch: branchName], [$class: 'CleanBeforeCheckout'], [$class: 'CloneOption', depth: 1, noTags: false, reference: '', shallow: true, timeout: 10]], submoduleCfg: [], userRemoteConfigs: [[url: 'git@github.corp.xxxx.com:'+orgName+'/'+repoName+'.git']]]) { note: I've also tried ^ shallow clone command without specifying 'depth: 1', but shows same behavior }

3. Shallow clone using shell command : 
sh "git clone --depth 1 git@github.xxx.com:Test/repoxyz.git -b master"