Re: Git 2.18: RUNTIME_PREFIX... is it working?

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Peff,

On Mon, 9 Jul 2018, Jeff King wrote:

> On Sun, Jul 08, 2018 at 11:52:22PM +0200, Johannes Schindelin wrote:
> 
> > Now, if you care to have a look at Dan's (and my) patches to implement
> > RUNTIME_PREFIX so that it looks for a directory *relative to the Git
> > binary*, you will see that it is far from portable. In fact, it is very
> > definitely not portable, and needs specific support for *every single
> > supported Operating System*. And while we covered a lot, we did not cover
> > all of them.
> > 
> > So unfortunately, it is impossible to make it the default, I am afraid.
> 
> Would it be reasonable to make RUNTIME_PREFIX the default on systems
> where we _do_ have that support? AFAIK there is no downside to having it
> enabled (minus a few syscalls to find the prefix, I suppose, but I
> assume that's negligible).
> 
> I.e., a patch to config.mak.uname (and possibly better support for
> _disabling_ it, though I think "make RUNTIME_PREFIX=" would probably
> work).

The obvious downside is that we would be a lot more likely to break one
side of the equation. At least right now, we have Git for Windows being a
prime user of RUNTIME_PREFIX (so breakages should be caught relatively
quickly), and macOS/Linux *not* being users of that feature (so breakages
in the non-RUNTIME_PREFIX code paths should be caught even quicker). By
turning on RUNTIME_PREFIX for the major platforms, the fringe platforms
are even further out on their own.

Ciao,
Dscho