We have a multi-branch pipeline project that produces artifacts, we also have a freeform project that is configured with build parameters to copy artifacts from the pipeline job based on the parameters supplied.

When I set the project name parameter to something like

myproject/${BRANCH_NAME} 

the job fails with

Unable to find project for artifact copy: myproject/mybranch

If it set the project name parameter to

myproject/mybranch

it works fine.

We aren't using matrix permissions, logged in users can do anything and Allow anonymous read access is checked. I tried setting the project property CopyArtifactPermissionProperty in the JenkinsFile to

properties([[$class: 'CopyArtifactPermissionProperty', projectNames: '*']])

but this made no difference.