I have been looking a bit into LLDB recently and I believe that I may have a sufficiently reasonable workaround for enabling the REPL on Windows to the point where it could be useful to have some early adopters experimenting and identifying problem areas. This is all lead work to help improve debugging on Windows, but we may be able to pre-identify some of the areas that will need to be improved. This will require some amount of patience and investigation in case of issues, but if anyone is motivated to try this out and report any feedback, I would appreciate that.
With the 2023-04-11-a snapshot of Swift, you will need to add a parameter to the invocation, which is the location of the runtime installation. Something like:
swift repl "-L%ProgramFiles%\swift\runtime-development\usr\bin"
Locally, this required expanding out the variable and quoting the spaces so it ends up being more:
swift repl "-LS:\Program\ Files\swift\runtime-development\usr\bin"
While not exactly the ideal state, it would be good to ensure that there are no other issues that are lurking, and I hope that we can get the default library search path resolved soon.