Not anymore persisting the /workspace content populated by custom .Dockerfile

[complyue]

Bug description

Content populated under /workspace/ during custom .dockerfile building, ultimately get lost when the workspace is started.

Steps to reproduce

https://gitpod.io/#https://github.com/complyue/tour/blob/master/welcome.edh

Workspace affected

No response

Expected behavior

Haskell toolchain (GHCup and pieces it installs) installed during custom .Dockerfile building should persist as before.

Example repository

https://github.com/complyue/tour

Anything else?

It works before, not been touching the env until recently. /workspace should persist, right?