file path issue when using infoplist file

It is a little complicated. My project structure is shown as follow:

• repo root dir
  • source files dir
    • code dir1
      • Info.plist
    • code dir2
    • ...
  • prjcect files dir
    • xxx.xcodeproj
    • xxx.xcworkspace
    • Podfile
    • Pods
  • project.yml

When i configurated in project.yml file as follow:

targets:
  Example:
    type: application
    sources:
        - path: source files dir/code dir1
          excludes: [Info.plist]
        - path: source files dir/code dir1/Info.plist
          buildPhase: none
    info:
      path: ${PROJECT_DIR}/../source files dir/code dir1/Info.plist  // s1
      path: ../source files dir/code dir1/Info.plist  // s2

Using s1, it creates a directory called ${PROJECT_DIR} in repo root dir. And ${PROJECT_DIR} is empty.
Using s2, it creates a directory in the parent directory of the repo root dir directory which contains the Info.plist file.

Both these 2 ways are weird and do not meets my expectations.

Is this intentional or a bug?

Start with the project.yml paths shown in the report and trace how XcodeGen resolves the info.path value relative to the repository and project directories. Reproduce both ${PROJECT_DIR}/... and ../... cases with the described layout, then verify that the generated project references the existing Info.plist without creating unexpected directories.