WSL and elisp

Hi I am trying to use `browse-url` function in emacs running inside wsl. And I get error: `No usable browser found`.

Which makes me think of changing `browse-url-default-browser`. But there is no system-type "wsl" or "gnu/linux/nt" (gnu running on linux on nt).

operating-system-release is nil on win10 (gnu.org) seems to denote one of the way to find if running on wsl (but that way seems to use bug as feature).

Another way would be checking for existence of "cmd.exe" or other windows executables (including "wsl.exe") in the PATH and use that as proxy as wsl.

I wonder if there would be a portable way to find out if emacs is running in wsl.

I would like to know what others think 😊

Thanking you.