Environment variables are not resolved in 'Advanced clone behaviours' -> 'Path of the reference repo to use during clone' when configuring git reference repository in the Pipeline SCM section.

Steps to reproduce:

• Create pipeline project
• In configure: fill in repository URL, Branch Specifier and Script Path (Jenkinsfile).
• In 'Additional Behaviours' select 'Advanced Clone Behaviours'. Set 'Path of the reference repo to use during clone' to some value depending on an environment variable, e.g. ${HOME}/jenkins/reference/big-git-repo.git
• At URL, create a git repository with Jenkinsfile. Put 'node('master') { checkout scm }' in the Jenkinsfile.
• Run the job. It will report: 

  Cloning repository ...URL...
   > git init ... # timeout=10
  ERROR: Reference path does not exist: ${HOME}/jenkins/reference/big-git-repo.git

Would be very handy to have this feature. In my case, I want to use the 'checkout scm' shortcut in a pipeline script that runs several builds in parallel on different platforms. So I want to specify where a reference repository exists on a specific node. For instance, on a Windows node I want to put it in D:\jenkins\reference, on a Mac – to /Users/jenkins/reference and, finally, on linux – /home/jenkins/reference. I could set an environment variable ${REFERENCE} to the above values in node configuration and than use it in 'Path of the reference repo to use during clone' as ${REFERENCE}.