help function tries to execute cmd.exe on Linux

[alex-fu27]

I am using fish, version 3.1.0 on Arch Linux. It is a dual boot setup with Windows 10. The Windows partition is mounted on /mnt/c.

When I run help, the following happens:

alex@alexnb ~> sh -c 'env HOME=$(mktemp -d) LANG= fish'                                                                                                                    
Welcome to fish, the friendly interactive shell
Type `help` for instructions on how to use fish
alex@alexnb /h/alex> help
Failed to execute process '/mnt/c/Windows/System32/cmd.exe'. Reason:
exec: Exec format error
The file '/mnt/c/Windows/System32/cmd.exe' is marked as an executable but could not be run by the operating system.
alex@alexnb /h/alex [125]>

The problem is caused by line 80 in help.fish:

if not type -q cygstart
    and set -l cmd (command -s cmd.exe /mnt/c/Windows/System32/cmd.exe)
    # Use the first of these.
    set fish_browser $cmd[1]
end

As this path exists on my system and is marked as executable, fish_browser will be set to that path.

I will work around it by setting the BROWSER variable.