Suggestion: drop 'g' in git-describe suffix

Suggestion: drop 'g' in git-describe suffix

[Han-Wen Nienhuys]

hi,

the convention to use a 'g' in the output of git-describe, eg.

   [lilydev@haring lilypond]$ git describe --abbrev=39
   lilypond_2_9_7-g47778d2297276484c861fc7536da13feb2d5fe8


is confusing: the g is also a hex digit, and without reading the manual 
carefully, you'd think this is the commit g4777.

Proposal: why not use

   tag#sha1

or some other non-hex character.

-- 
  Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

Re: Suggestion: drop 'g' in git-describe suffix

[Andy Whitcroft]

Han-Wen Nienhuys wrote:
> 
> hi,
> 
> the convention to use a 'g' in the output of git-describe, eg.
> 
>   [lilydev@haring lilypond]$ git describe --abbrev=39
>   lilypond_2_9_7-g47778d2297276484c861fc7536da13feb2d5fe8
> 
> 
> is confusing: the g is also a hex digit, and without reading the manual
> carefully, you'd think this is the commit g4777.
> 
> Proposal: why not use
> 
>   tag#sha1
> 
> or some other non-hex character.

g is not a hex digit, hex is 0-f ??

In current versions of git, this whole string is also a valid name for
the commit ie you can do the following:

	git show lilypond_2_9_7-g47778d2297276484c861fc7536da13feb2d5fe8

-apw

Re: Suggestion: drop 'g' in git-describe suffix

[Han-Wen Nienhuys]

Andy Whitcroft escreveu:
>> or some other non-hex character.
> 
> g is not a hex digit, hex is 0-f ??
> 

Yes of course; silly me. Still I think it would be clearer if it used a 
non-alphabet char, eg.

   tag+sha1

to separate the tag and the committish.

-- 
  Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

Re: Suggestion: drop 'g' in git-describe suffix

[Andy Whitcroft]

Han-Wen Nienhuys wrote:
> Andy Whitcroft escreveu:
>>> or some other non-hex character.
>>
>> g is not a hex digit, hex is 0-f ??
>>
> 
> Yes of course; silly me. Still I think it would be clearer if it used a
> non-alphabet char, eg.
> 
>   tag+sha1
> 
> to separate the tag and the committish.

Well there is a non-alphabet character in there, a minus (-).  The g
prefix on the sha1 _fragment_ it to indicate that it is in fact a
truncated sha1, not a complete one.  If you want the complete clean sha1
this is not the way to get it?

Re: Suggestion: drop 'g' in git-describe suffix

[Han-Wen Nienhuys]

Andy Whitcroft escreveu:
> Han-Wen Nienhuys wrote:
>> Andy Whitcroft escreveu:
>>>> or some other non-hex character.
>>> g is not a hex digit, hex is 0-f ??
>>>
>> Yes of course; silly me. Still I think it would be clearer if it used a
>> non-alphabet char, eg.
>>
>>   tag+sha1
>>
>> to separate the tag and the committish.
> 
> Well there is a non-alphabet character in there, a minus (-).  The g
> prefix on the sha1 _fragment_ it to indicate that it is in fact a
> truncated sha1, not a complete one.  

is this policy documented somewhere?  None of the tools understand it.

[lilydev@haring git]$ git describe
v1.4.3.3-g1e1f76e
[lilydev@haring git]$ git show g1e1f76e
fatal: ambiguous argument 'g1e1f76e': unknown revision or path not in 
the working tree.
Use '--' to separate paths from revisions

My suggestion is to use

   v1.4.3.3+1e1f76e

here.

> If you want the complete clean sha1
> this is not the way to get it?


-- 
  Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

Re: Suggestion: drop 'g' in git-describe suffix

[Johannes Schindelin]

Hi,

On Thu, 2 Nov 2006, Han-Wen Nienhuys wrote:

> [lilydev@haring git]$ git describe
> v1.4.3.3-g1e1f76e
> [lilydev@haring git]$ git show g1e1f76e

You'd want to do

	git show v1.4.3.3-g1e1f76e

Hth,

Re: Suggestion: drop 'g' in git-describe suffix

[Santi Béjar]

On 11/2/06, Han-Wen Nienhuys <hanwen@xs4all.nl> wrote:
> Andy Whitcroft escreveu:
> > Han-Wen Nienhuys wrote:
> >>
> >>   tag+sha1
> >>
> >> to separate the tag and the committish.
> >
> > Well there is a non-alphabet character in there, a minus (-).  The g
> > prefix on the sha1 _fragment_ it to indicate that it is in fact a
> > truncated sha1, not a complete one.

I think it is there to indicate it is a git commit sha1.

>
> is this policy documented somewhere?  None of the tools understand it.
>
> [lilydev@haring git]$ git describe
> v1.4.3.3-g1e1f76e
> [lilydev@haring git]$ git show g1e1f76e
> fatal: ambiguous argument 'g1e1f76e': unknown revision or path not in
> the working tree.
> Use '--' to separate paths from revisions
>

Use the complete output of describe:
$ git show v1.4.3.3-g1e1f76e

or the abbrev sha1:
$ git show 1e1f76e

> My suggestion is to use
>
>    v1.4.3.3+1e1f76e

My suggestion is to use:

v1.4.3.3-git1e1f76e

to make clear that it is a git revision version.

One problem I see with this scheme (either 'g', 'git' of '+') is that
it does not provide an increasing version number, even for
fast-forwarding commits. Then it is not useful as a package version
number (deb or rpm). I've already seen deb packages with
version+git20061010. One possibility could be to add the number of
commits between the tag and the commit as:

v1.4.3.3-git12g1e1f76e

to provide a weak ordering for fast-forwarding commits. What do you thing?

Re: Suggestion: drop 'g' in git-describe suffix

[Andy Whitcroft]

Santi Béjar wrote:
> On 11/2/06, Han-Wen Nienhuys <hanwen@xs4all.nl> wrote:
>> Andy Whitcroft escreveu:
>> > Han-Wen Nienhuys wrote:
>> >>
>> >>   tag+sha1
>> >>
>> >> to separate the tag and the committish.
>> >
>> > Well there is a non-alphabet character in there, a minus (-).  The g
>> > prefix on the sha1 _fragment_ it to indicate that it is in fact a
>> > truncated sha1, not a complete one.
> 
> I think it is there to indicate it is a git commit sha1.
> 
>>
>> is this policy documented somewhere?  None of the tools understand it.
>>
>> [lilydev@haring git]$ git describe
>> v1.4.3.3-g1e1f76e
>> [lilydev@haring git]$ git show g1e1f76e
>> fatal: ambiguous argument 'g1e1f76e': unknown revision or path not in
>> the working tree.
>> Use '--' to separate paths from revisions
>>
> 
> Use the complete output of describe:
> $ git show v1.4.3.3-g1e1f76e
> 
> or the abbrev sha1:
> $ git show 1e1f76e
> 
>> My suggestion is to use
>>
>>    v1.4.3.3+1e1f76e
> 
> My suggestion is to use:
> 
> v1.4.3.3-git1e1f76e
> 
> to make clear that it is a git revision version.
> 
> One problem I see with this scheme (either 'g', 'git' of '+') is that
> it does not provide an increasing version number, even for
> fast-forwarding commits. Then it is not useful as a package version
> number (deb or rpm). I've already seen deb packages with
> version+git20061010. One possibility could be to add the number of
> commits between the tag and the commit as:
> 
> v1.4.3.3-git12g1e1f76e
> 
> to provide a weak ordering for fast-forwarding commits. What do you thing?

I think you'll restart the 1.2.3.4 versioning is better 'debate' again!

Surly if things are being pushed into a .deb or .rpm we should be using
a real release version.  We should be tagging that.  If the project is
not providing release number, there is nothing stopping you from tagging
them yourself in your copy of the repository and using your tag.  you
could use like 'unofficial-N' where N increments in the way you want.

Re: Suggestion: drop 'g' in git-describe suffix

[Santi Béjar]

On 11/2/06, Andy Whitcroft <apw@shadowen.org> wrote:
> Santi Béjar wrote:
> > One problem I see with this scheme (either 'g', 'git' of '+') is that
> > it does not provide an increasing version number, even for
> > fast-forwarding commits. Then it is not useful as a package version
> > number (deb or rpm). I've already seen deb packages with
> > version+git20061010. One possibility could be to add the number of
> > commits between the tag and the commit as:
> >
> > v1.4.3.3-git12g1e1f76e
> >
> > to provide a weak ordering for fast-forwarding commits. What do you thing?
>
> I think you'll restart the 1.2.3.4 versioning is better 'debate' again!

Sorry, I don't undestand this.

> Surly if things are being pushed into a .deb or .rpm we should be using
> a real release version.  We should be tagging that.  If the project is
> not providing release number, there is nothing stopping you from tagging
> them yourself in your copy of the repository and using your tag.  you
> could use like 'unofficial-N' where N increments in the way you want.

And where do you store this tag? It is an upstream commit and you just
refer to this. With the unofficial-N there is no way to know which
upstream commit you are refering without having access to the git
repository of the packager  .

Re: Suggestion: drop 'g' in git-describe suffix

[Andy Whitcroft]

Santi Béjar wrote:
> On 11/2/06, Andy Whitcroft <apw@shadowen.org> wrote:
>> Santi Béjar wrote:
>> > One problem I see with this scheme (either 'g', 'git' of '+') is that
>> > it does not provide an increasing version number, even for
>> > fast-forwarding commits. Then it is not useful as a package version
>> > number (deb or rpm). I've already seen deb packages with
>> > version+git20061010. One possibility could be to add the number of
>> > commits between the tag and the commit as:
>> >
>> > v1.4.3.3-git12g1e1f76e
>> >
>> > to provide a weak ordering for fast-forwarding commits. What do you
>> thing?
>>
>> I think you'll restart the 1.2.3.4 versioning is better 'debate' again!
> 
> Sorry, I don't undestand this.

There was a long running debate between sha1's and version 'numbers'
1.2.3.4 for each revision.
> 
>> Surly if things are being pushed into a .deb or .rpm we should be using
>> a real release version.  We should be tagging that.  If the project is
>> not providing release number, there is nothing stopping you from tagging
>> them yourself in your copy of the repository and using your tag.  you
>> could use like 'unofficial-N' where N increments in the way you want.
> 
> And where do you store this tag? It is an upstream commit and you just
> refer to this. With the unofficial-N there is no way to know which
> upstream commit you are refering without having access to the git
> repository of the packager  .

Yes that is completly true, but its normally the packer who is doing the
bug fixing of the .deb when its broken.  The key problem is you need
your numbering to be stable.  The only guarenteed stable thing is the
sha1, tags can change.  IMHO you should be including the full sha1 in
the --version output and the package descript, whatever versioning you
are using on the .deb itself.

That said I guess it would be pretty easy to come up with something to
count the number of commits since the last valid tag, something like
that below.  Might not be pretty, nor so easy to turn back into a commit
of course.

-apw

#!/bin/sh

let n=0
git log --pretty=one "$@" | \
        awk '{print $1}' | \
        git name-rev --tags --stdin | \
{
        while read sha1 name
        do
                if [ "$name" != "" ]; then
                        echo "$sha1 $name $n"
                        exit 0
                fi
                let "n=n+1"
        done
        echo "- unknown 0"
        exit 1

Re: Suggestion: drop 'g' in git-describe suffix

[Han-Wen Nienhuys]

Santi Béjar escreveu:
> One problem I see with this scheme (either 'g', 'git' of '+') is that
> it does not provide an increasing version number, even for
> fast-forwarding commits. Then it is not useful as a package version
> number (deb or rpm). I've already seen deb packages with
> version+git20061010. One possibility could be to add the number of
> commits between the tag and the commit as:
> 
> v1.4.3.3-git12g1e1f76e
> 
> to provide a weak ordering for fast-forwarding commits. What do you thing?

Is that number well defined if you merge branches in between?

I'd prefer

   v1.4.3.3+git-12-1e1f76e

or similar. Pasting together words without separator is bad for readability.

-- 

Re: Suggestion: drop 'g' in git-describe suffix

[Santi Béjar]

On 11/2/06, Han-Wen Nienhuys <hanwen@xs4all.nl> wrote:
> Santi Béjar escreveu:
> > One problem I see with this scheme (either 'g', 'git' of '+') is that
> > it does not provide an increasing version number, even for
> > fast-forwarding commits. Then it is not useful as a package version
> > number (deb or rpm). I've already seen deb packages with
> > version+git20061010. One possibility could be to add the number of
> > commits between the tag and the commit as:
> >
> > v1.4.3.3-git12g1e1f76e
> >
> > to provide a weak ordering for fast-forwarding commits. What do you thing?
>
> Is that number well defined if you merge branches in between?

Yes.

$ git-rev-list 1e1f76e ^v1.4.3.3 | wc -l

>
> I'd prefer
>
>    v1.4.3.3+git-12-1e1f76e
>
> or similar. Pasting together words without separator is bad for readability.
>
> --
>   Han-Wen Nienhuys - hanwen@xs4all.nl - http://www.xs4all.nl/~hanwen

Re: Suggestion: drop 'g' in git-describe suffix

[Jakub Narebski]

Han-Wen Nienhuys wrote:

> Santi Béjar escreveu:
>> One problem I see with this scheme (either 'g', 'git' of '+') is that
>> it does not provide an increasing version number, even for
>> fast-forwarding commits. Then it is not useful as a package version
>> number (deb or rpm). I've already seen deb packages with
>> version+git20061010. One possibility could be to add the number of
>> commits between the tag and the commit as:
>> 
>> v1.4.3.3-git12g1e1f76e
>> 
>> to provide a weak ordering for fast-forwarding commits. What do you thing?
> 
> Is that number well defined if you merge branches in between?
> 
> I'd prefer
> 
>    v1.4.3.3+git-12-1e1f76e
> 
> or similar. Pasting together words without separator is bad for readability.

Or even IMVHO better:

    v1.4.3.3+12--1e1f76e

or something like that. v1.4.3.3+12 part meaning that v1.4.3.3 is 12 ancestor
in direct shortest direct line, or that v1.4.3.3+12 is 12 generations away
from v1.4.3.3.

Of course that is _costly_ to confitm that, and v1.4.3.3+12 might mean more
than one revision in presence of branching points, especially that there is
no equivalent of "first parent" to distinguish like in case of v1.4.3.3~12
-- 
Jakub Narebski
Warsaw, Poland
ShadeHawk on #git

Re: Suggestion: drop 'g' in git-describe suffix

[Nicolas Vilz 'niv']

Santi Béjar wrote:
> On 11/2/06, Han-Wen Nienhuys <hanwen@xs4all.nl> wrote:
>> Andy Whitcroft escreveu:
>> > Han-Wen Nienhuys wrote:
>> >>
>> >>   tag+sha1
>> >>
>> >> to separate the tag and the committish.
>> >
>> > Well there is a non-alphabet character in there, a minus (-).  The g
>> > prefix on the sha1 _fragment_ it to indicate that it is in fact a
>> > truncated sha1, not a complete one.
> 
> I think it is there to indicate it is a git commit sha1.
> 
>>
>> is this policy documented somewhere?  None of the tools understand it.
>>
>> [lilydev@haring git]$ git describe
>> v1.4.3.3-g1e1f76e
>> [lilydev@haring git]$ git show g1e1f76e
>> fatal: ambiguous argument 'g1e1f76e': unknown revision or path not in
>> the working tree.
>> Use '--' to separate paths from revisions
>>
> 
> Use the complete output of describe:
> $ git show v1.4.3.3-g1e1f76e

this one doesn't work for me in my repository.

$ git-describe
release_1_22_v0.7-g85eb121

$ git show release_1_22_v0.7-g85eb121
fatal: ambiguous argument 'release_1_22_v0.7-g85eb121': unknown revision 
or path not in the working tree.
Use '--' to separate paths from revisions


> or the abbrev sha1:
> $ git show 1e1f76e
this one works with my repository

$ git show 85eb121

i use git version 1.4.2.rc2.g2686c

(that was next branch of git one or two days ago or so..)

it would be great to let the full output of git describe work as well.

Sincerly

Re: Suggestion: drop 'g' in git-describe suffix

[Johannes Schindelin]

Hi,

On Thu, 2 Nov 2006, Nicolas Vilz 'niv' wrote:

> > Use the complete output of describe:
> > $ git show v1.4.3.3-g1e1f76e
> 
> this one doesn't work for me in my repository.

You need at least v1.4.3-rc1^0~69 (v1.4.2.1-g7dd45e1) for this. You 
indicated in your email that your version is older.

Ciao,
Dscho

Re: Suggestion: drop 'g' in git-describe suffix

[Nicolas Vilz 'niv']

Johannes Schindelin wrote:
> Hi,
> 
> On Thu, 2 Nov 2006, Nicolas Vilz 'niv' wrote:
> 
>>> Use the complete output of describe:
>>> $ git show v1.4.3.3-g1e1f76e
>> this one doesn't work for me in my repository.
> 
> You need at least v1.4.3-rc1^0~69 (v1.4.2.1-g7dd45e1) for this. You 
> indicated in your email that your version is older.

strange, from time to time i have to delete the whole git repository, 
not to get stuck on old revisions. Now with a fresh repository i get a 
current revision and with this version, it works.

Thx for help

Re: Suggestion: drop 'g' in git-describe suffix

[Andy Whitcroft]

Han-Wen Nienhuys wrote:
> Andy Whitcroft escreveu:
>> Han-Wen Nienhuys wrote:
>>> Andy Whitcroft escreveu:
>>>>> or some other non-hex character.
>>>> g is not a hex digit, hex is 0-f ??
>>>>
>>> Yes of course; silly me. Still I think it would be clearer if it used a
>>> non-alphabet char, eg.
>>>
>>>   tag+sha1
>>>
>>> to separate the tag and the committish.
>>
>> Well there is a non-alphabet character in there, a minus (-).  The g
>> prefix on the sha1 _fragment_ it to indicate that it is in fact a
>> truncated sha1, not a complete one.  
> 
> is this policy documented somewhere?  None of the tools understand it.
> 
> [lilydev@haring git]$ git describe
> v1.4.3.3-g1e1f76e
> [lilydev@haring git]$ git show g1e1f76e
> fatal: ambiguous argument 'g1e1f76e': unknown revision or path not in
> the working tree.
> Use '--' to separate paths from revisions
> 
> My suggestion is to use
> 
>   v1.4.3.3+1e1f76e
> 
> here.

The 'whole' thing is valid as an object reference:

apw@pinky$ git describe
v1.4.3.3-g8cf249b
apw@pinky$ git show v1.4.3.3-g8cf249b
commit 8cf249b755c257ea19100b888ac612e601cdf96b
Merge: 15c3ffb... fa438a2...
[...]

Re: Suggestion: drop 'g' in git-describe suffix

[Petr Baudis]

Dear diary, on Thu, Nov 02, 2006 at 11:37:31AM CET, I got a letter
where Andy Whitcroft <apw@shadowen.org> said that...
> The g prefix on the sha1 _fragment_ it to indicate that it is in fact
> a truncated sha1, not a complete one.

I think it's rather to indicate that it is a sha1 at all.

-- 
				Petr "Pasky" Baudis
Stuff: http://pasky.or.cz/
#!/bin/perl -sp0777i<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<j]dsj
$/=unpack('H*',$_);$_=`echo 16dio\U$k"SK$/SM$n\EsN0p[lN*1

Re: Suggestion: drop 'g' in git-describe suffix

[Carl Worth]

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On Thu, 2 Nov 2006 12:03:31 +0100, Petr Baudis wrote:
>
> Dear diary, on Thu, Nov 02, 2006 at 11:37:31AM CET, I got a letter
> where Andy Whitcroft <apw@shadowen.org> said that...
> > The g prefix on the sha1 _fragment_ it to indicate that it is in fact
> > a truncated sha1, not a complete one.
>
> I think it's rather to indicate that it is a sha1 at all.

Frankly, I've never understood the 'g' prefix at all. I don't use
git-describe much, but some people have sent me things with this 'g'
on the front and every time I've received that I was annoyed to find
the commit identifier they sent didn't work until I manually removed
it.

It's definitely never provided any useful semantic information to me.

-Carl

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