Unable to launch debugger with fish shell as default system shell.

I am working on OS X (10.10.5). I prefer to have my login shell set to fish (/usr/local/bin/fish). However, this appears to break the method currently being used by the extension to launch external console commands.

Specifically, the terminal window that pops up (not a big deal, but it would be "nice" if the extension used the internal debugger settings--I prefer iTerm.app to terminal.app) is pretty obviously expecting a bash shell. My default shell (fish) fails pretty miserably with the given commands, and VS Code quite nicely gives the following message:

Unable to start debugging. Failed to initialize debugger terminal.

Basically I am asking this: is there a method for forcing the external command to use a bash environment instead of the default system environment?

I'd prefer to not have to switch back and forth just to run the debugger (which works fantastically when I switch the system login shell to bash).

Start by reproducing the debugger-terminal failure on OS X with fish configured as the login shell, then inspect the extension's external console command launch path and how it selects the shell. Done means the debugger launches successfully without changing the system login shell, while preserving the existing bash behavior.