Re: [PATCH v1 0/2] git-gui: reduce Tcl version requirement from 8.6 to 8.5

From: Pratyush Yadav <me@yadavpratyush.com>
Date: Mar 17, 2020, 12:49 UTC
Message-ID: <20200317124902.fitwgrrm6jtv24ec@yadavpratyush.com>
In-Reply-To: <xmqqwo7k8fnk.fsf@gitster.c.googlers.com>

On 16/03/20 08:48AM, Junio C Hamano wrote:

Show 20 quoted lines

> Eric Sunshine <sunshine@sunshineco.com> writes:
> 
> > On Sat, Mar 14, 2020 at 9:47 PM Pratyush Yadav <me@yadavpratyush.com> wrote:
> >> Some MacOS distributions ship with Tcl 8.5. This means we can't use
> >> TclOO. So, use our homegrown class.tcl instead.
> >
> > It should be mentioned that this patch series fixes a regression in
> > Git v2.25 in which git-gui could not even be launched on Mac OS. The
> > problem was reported here[1] a couple months ago.
> >
> > I performed some rudimentary testing of this patch series on Mac OS,
> > and it appears to be working as expected; it certainly fixes the
> > problem of git-gui not launching on Mac OS. (I did notice a
> > misbehavior related to the original patch which caused git-gui to be
> > unusable on Mac OS in v2.25, but I suspect that misbehavior is not
> > related to or caused by this patch series, thus shouldn't prevent its
> > acceptance.)
> 
> I was actually hesitant to see this kind of change for the first
> time this late in the cycle

*sigh* I intended to finish the change much sooner, but one thing after another, and I kept putting it on the backburner :-(

> (the code may work with old Tcl/Tk but do we know it does with newer 
> ones?)

It is actually the other way around. My system has Tcl 8.6 installed, and it works well with it. The problem is checking if it works with 8.5. My distro's package manager doesn't show Tcl 8.5 as an option (only 8.6), so I have to try and build 8.5 from source to test it. It is more work than I can afford right now. So I am relying on Eric and other MacOS users' reports.

But IIUC, unless there are any hidden gotchas in Tcl 8.5, there is a 
fairly little chance that this patch breaks anything significant that 
wasn't already broken before. The patch reverts from using a new 
8.6-specific feature to pure, backward-compatible Tcl that should work 
with older versions too. No, a larger concern for me is whether I missed 
something somewhere that breaks the feature for _all_ versions of 
git-gui.

Show 5 quoted lines

> I'll pull git-gui updates when Pratyush tells me to, which would
> happen before the final (scheduled on 22nd).  I'll trust git-gui
> maintainer's decision to include these changes in it, or to cook
> longer to wait for the 2.27 cycle.  Comments like yours that help
> Pratyush make the right judgment is greatly appreciated.

Honestly, I'd like to cook it a bit longer but the reality is that very few people, if any, actually track and test my tree. Most people actually discover bugs when the changes hit a new Git release.

I cooked the original series that bumped the version requirement for quite some time because I suspected some platforms might still be on older versions. But I got absolutely no feedback/complaints, so I went ahead and sent you a pull request.

The change hit my 'master' on December 6. Git v2.25.0 was tagged on January 13th. MacOS breakage was reported on January 15th.

So, I have a choice between waiting for the 2.27 cycle keeping git-gui broken on MacOS for another few months in hopes that someone comes in and discovers a bug, or have it merged in v2.26 fixing git-gui for MacOS but risk (though it shouldn't be too high) introducing a bug in _all_ platforms. Neither choice is ideal, but I'm leaning towards the latter. Having _most_ things working is better than having nothing working at all.

-- 
Regards,
Pratyush Yadav