Use source flag or node-style query key (`path:`) to lock 1 specific origin

[zm-cttae]

I'd prefer to install a package from only file exchange sometimes, or github sometimes. Especially when names could clash!
Preferably, we should have the choice to force a specific source and then error out on 404 from that origin.

[mobeets]

As it is currently, it searches file exchange first, and then github. You can pass --github-first or -g to search github first. Does that help with what you're looking for, or slightly different?

[zm-cttae]

This would be about locking search to one registry - in case we want to avoid unrelated GitHub scripts for example!

[mobeets]

Gotcha, this sounds like a pretty simple fix. Mostly just adding a new name-value argument, -s for source, and then updating the function findUrl. If you want to take a stab at it and make a pull-request, please do!