How to use two formulas with conflicting binary names

[crunchtime-ali]

I recently added the bit-git formula to homebrew-core which I symlink to bit because there was already a formula for bit.

Some bit-git users which also use the other bit formula have been asking how they can install both formula (the bit-git one has a conflicts_with key).
Is that possible without modifying the formula or do the users have to resort to install one of them without Homebrew?

[gromgit]

There can be only one /usr/local/bin/bit at any one time, no matter which formula it comes from.

Users can install both formulae, but they need to brew unlink whichever one's already installed, before installing the other formula. brew link/unlink controls which formula's files are symlinked into the main /usr/local hierarchy, but both formulae's files can be accessed independently under /usr/local/opt/{bit,bit-git}.

[MultifokalHirn]

but I would say it is conceivable that brew could have a feature to work around such conflicts, through aliases or some such

[gromgit]

As I see it, the show-stopper is organizational, not technical. When you have two (or more) packages with conflicting names...

1. Who gets to keep the original name? (Everyone else has to be renamed, and when each program does something different, users may be in for a BIG surprise when xyzzy doesn't behave the way they thought. Any scripts/programs that expect a particular xyzzy may then malfunction with disastrous consequences.)
2. Who decides? (No one will be happy with this person.)
3. What happens when a new package introduces an unforeseen conflict?
4. What happens when that new package is in a third-party repo?

"Closed-development" Linux distros like Debian solve [1] through [3] by being "masters of their domains". They decide internally which packages go into the distros, so the name of every binary in an "all-packages" install is known before release, and they can decide which programs get renamed and make those decisions stick, but as far as I know, none of them have a solution for [4].

"Open-contribution" Linux distros like Arch face exactly the same problem as Homebrew. As far as I know, Arch chose to punt the problem to the user ("someone's gotta rename something, we won't let you install both"). Homebrew chose (in my mind) a more useful path: you can install conflicting formulae (say, foobar and burtle), but you'll have to brew unlink them first, then you can decide that, say, the xyzzy program from foobar is more useful to you, so brew link foobar to make that xyzzy available without full pathname, and refer to the other one as ${HOMEBREW_PREFIX}/opt/burtle/bin/xyzzy, or temporarily prepend ${HOMEBREW_PREFIX}/opt/burtle/bin to your PATH, or brew unlink foobar; brew link burtle as and when your needs change.

If you can come up with an alternative solution that sidesteps [1] through [3], without negating Homebrew's "open-contribution" commitment, please file a PR to improve the situation.