Re: [PATCH] clone: --dissociate option to mark that reference is only temporary

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 16, 2014, 19:27 UTC
Message-ID: <xmqqegu7u85m.fsf@gitster.dls.corp.google.com>
In-Reply-To: <xmqqwq81w8az.fsf@gitster.dls.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 24 quoted lines

> Marc Branchaud <marcnarc@xiplink.com> writes:
>
>> I think things would be more understandable if the option was "--dissociate
>> <repository>" and was an explicit alternative to --reference:
>> 	[[--reference | --dissociate] <repository>]
>>
>> I'm still not liking the name "--dissociate" though.  The original suggestion
>> of "--borrow" is better.  Perhaps "--library" or "--local-cache"?  I dunno...
>
> I was not thinking when I originally started the topic with
> "--borrow", until I realized that it would not make much sense,
> primarily because we allow multiple references.
>
> What should this command line do, and how would you implement such a
> behaviour?
>
>     $ git clone \
>         --reference=/local/pool/linux.git \
>         --borrow=../my/neighbour/linux-hack.git \
>         git://git.kernel.org/...../linux.git
>
> With "do the usual --reference thing, but then dissociate the result
> from referents" option, there is no ambiguity and that is why I did
> not go with the "--borrow" option suggested in the original thread.

Another approach we could take is to add --borrow and then forbid mixing --reference and --borrow on the same command line, until somebody comes up with an implementation to allow us dissociate from borrowed repositories while still depending on referenced ones, at which time we can lift that limitation.

But if that future extension is not going to happen, there is not much difference. The end result will be either

 - the one that is very clear to the users that they cannot
   selectively dissociate because there is no such option documented
   (i.e. --reference, --dissociate and no --borrow); and

 - the other one that gives a slight hope to the users that the
   combination might work (i.e. with --reference, --borrow and no
   --dissociate) but refuses to do so when it actually is run.

Between the two, the former might actually be easier to the users to understand, as it keeps their expectation in line with the reality.

So I dunno.

I certainly am *not* going to do the selective dissociation change myself. Do we have a volunteer (hint: this probably does not fall into "low-hanging fruit" category)?