Re: cleanups with long-term benefits (was Re: [PATCH] schemas: Add vim modeline)

[John Snow <jsnow@redhat.com>]

On 8/5/20 3:36 AM, Markus Armbruster wrote:
> John Snow <jsnow@redhat.com> writes:
> 
>> On 8/4/20 4:03 AM, Markus Armbruster wrote:
>>> The pain of tweaking the parser is likely dwarved several times over by
>>> the pain of the flag day.
>>
>> You mention this often; I wonder if I misunderstand the critique,
>> because the pain of a "flag day" for a new file format seems
>> negligible to me.
>>
>> I don't think we edit these .json files very often. Generally, we add
>> a new command when we need one. The edits are usually one or two lines
>> plus docstrings.
>>
>> If anyone has patches in-flight, I genuinely doubt it will take more
>> than a few minutes to rewrite for the new file format.
>>
>> No?
> 
> You describe the the flag day's one-time pain.
> 
> There's also the longer term pain of having to work around git-blame
> unable to see beyond the flag day.
> 

So it's not really the "flag day" we're worried about anymore, it's the 
ongoing ease-of-use for vcs history.

> I'm not claiming the pain is prohibitive (if I thought it was, I
> would've tried to strange this thread in its crib), I am claiming it'll
> be much more painful (read: expensive) than a parser tweak.
> 

I do use `git blame` quite a lot, but with a project as old as QEMU, 
most of my trips through history do involve jumping across a few 
refactor gaps as a normal part of that process.

As Dan points out, I often have to back out and add refactorSHA^ to my 
invocation, and just keep hopping backwards until I find what I am truly 
after. It just feels like a fact of programmer life for me at this point.

I've not used Paolo's invocation before, but it looks like it might be 
useful. I'll try to remember to try it out.