Re: git silently ignores aliases of existing commands

From: Jeff King <peff@peff.net>
Date: Jul 18, 2009, 10:46 UTC
Message-ID: <20090718104631.GA27307@coredump.intra.peff.net>
In-Reply-To: <9b18b3110907180230p7fb432cdq56bfee794afc669e@mail.gmail.com>

On Sat, Jul 18, 2009 at 11:30:25AM +0200, demerphq wrote:

> Yeah it seems reasonable that if its going to be ignored it should not
> be silently ignored.

I agree that there should be a warning. However, it's hard to do with the code structured as it is now; we don't know that a command exists as an external command until we try to exec it. And if it succeeds, we don't get to execute any more code.

It's certainly possible, but sadly it is more surgery than just

  if (alias_lookup(cmd))
    warn("you also have an alias defined");

> Especially given that the silentness effectively means there cant be
> any new git tools added without possible breakage of installed setups.

The silentness makes it harder to diagnose problems, but even with a warning, we can break things by creating new commands. If you have an alias "foo" and we ship "git-foo" in a newer version of git, your alias will just stop working.

-Peff