Context: this is for a deployment on tag push

$CurrentTag and $TagMinusOne both work but $ChangeLog does not.

This might have been working at some point, but I can't seem to find any more information since these two issues:
https://help.appveyor.com/discussions/questions/2226-github-deploym...
https://help.appveyor.com/discussions/problems/1421-github-release-...

Here's my appveyor.yaml

version: b-{build}  
skip_non_tags: true  
configuration:  
- Debug
- Release
clone_depth: 1  
before_build:  
- ps: dotnet restore
build:  
  project: FrappeMocha.sln
  parallel: true
  verbosity: minimal
after_build:  
- ps: If(Test-Path -Path "bin\Release\*.exe") { Compress-Archive -Path bin\Release\*.exe -DestinationPath bin\Release\FrappeMocha-Release.zip } Else { Compress-Archive -Path bin\Debug\* -DestinationPath bin\Debug\FrappeMocha-Debug.zip }
artifacts:  
- path: bin\Release\FrappeMocha-Release.zip
  name: Release
- path: bin\Debug\FrappeMocha-Debug.zip
  name: Debug
before_deploy:  
- ps: >-
    $env:CurrentTag = git tag --sort=-committerdate | Select -Index (0)

    $env:TagMinusOne = git tag --sort=-committerdate | Select -Index (1)

    $ChangeLog = git log --pretty=format:%s $env:CurrentTag...$env:TagMinusOne

    $env:ChangeLog = $ChangeLog -join "\n"
deploy:  
- provider: GitHub
  tag: $(CurrentTag)
  release: Version $(CurrentTag)
  description: $(ChangeLog)
  auth_token:
    secure: iy+8lTlWIKPwbHYhYLcaJpHYlbP849yFUolLQ/wHBLXvVf+A7oQ8sq8s04oAghxA
  artifact: /.*\.zip/
  draft: true
  force_update: false

<pre><code>
Thanks again for running such an awesome service</code>
</pre>