emacs-repository-version not defined when cloned with mercurial

emacs-repository-version not defined when cloned with mercurial

[Uwe Brauer]

Hi 

I cloned the emacs repository with mercurial and compiled it as I always
do with

 ./configure --prefix=/opt/emacs27 --with-x-toolkit=athena --with-mailutils


But then emacs-repository-version returned till.

Any change to tell emacs to use the mercurial hash tag?

Regards

Uwe Brauer 

Re: emacs-repository-version not defined when cloned with mercurial

[Paul Eggert]

On 8/9/19 8:40 AM, Uwe Brauer wrote:
> Any change to tell emacs to use the mercurial hash tag?

Sorry, it's not clear what you're asking for here. If you'd like to 
write and debug the feature it sounds like it'd be a good thing to add 
to Emacs, though I wouldn't expect it to appear unless a Mercurial-using 
developer takes the initiative to develop it since it should be needed 
only by developers of Emacs.

Re: emacs-repository-version not defined when cloned with mercurial

[Sven Joachim]

On 2019-08-09 13:24 -0700, Paul Eggert wrote:

> On 8/9/19 8:40 AM, Uwe Brauer wrote:
>> Any change to tell emacs to use the mercurial hash tag?
>
> Sorry, it's not clear what you're asking for here. If you'd like to
> write and debug the feature it sounds like it'd be a good thing to add
> to Emacs, though I wouldn't expect it to appear unless a
> Mercurial-using developer takes the initiative to develop it since it
> should be needed only by developers of Emacs.

It might actually be a bit confusing to them if mercurial revision IDs
are included in bug reports, since those do not exist in the git
repository.  And I have not found a way to get the original git SHA1
back, at least it is not reported in "hg log --debug".

Cheers,
       Sven

Re: emacs-repository-version not defined when cloned with mercurial

[Uwe Brauer]

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>>> "PE" == Paul Eggert <eggert@cs.ucla.edu> writes:

> On 8/9/19 8:40 AM, Uwe Brauer wrote:
>> Any change to tell emacs to use the mercurial hash tag?

> Sorry, it's not clear what you're asking for here. If you'd like to
> write and debug the feature it sounds like it'd be a good thing to add
> to Emacs, though I wouldn't expect it to appear unless a
> Mercurial-using developer takes the initiative to develop it since it
> should be needed only by developers of Emacs.

I know mercurial reasonably well (but I am not a mercurial developer). I
am compiling and running the GNU emacs from the git repository.
As I said I cloned it to mercurial using the git plugin.
This plugin translate the git and the mercurial hash with out problem.

I looked now in the relevant code in version.el

It goes as follows:
#+begin_src elisp :noexport

(defun emacs-repository-version-git (dir)
  "Ask git itself for the version information for directory DIR."
  (message "Waiting for git...")
  (with-temp-buffer
    (let ((default-directory (file-name-as-directory dir)))
      (and (eq 0
	       (with-demoted-errors "Error running git rev-parse: %S"
		 (call-process "git" nil '(t nil) nil "rev-parse" "HEAD")))
	   (progn (goto-char (point-min))
		  (looking-at "[0-9a-fA-F]\\{40\\}"))
	   (match-string 0)))))


(defun emacs-repository-get-version (&optional dir external)
  "Try to return as a string the repository revision of the Emacs sources.
The format of the returned string is dependent on the VCS in use.
Value is nil if the sources do not seem to be under version
control, or if we could not determine the revision.  Note that
this reports on the current state of the sources, which may not
correspond to the running Emacs.

Optional argument DIR is a directory to use instead of `source-directory'.
Optional argument EXTERNAL is ignored."
  (emacs-repository-version-git (or dir source-directory)))
#+end_src

The git command 

git rev-parse HEAD

corresponds to the mercurial command 

hg parent --template '{node}\n'

I will try to implement the relevant 
emacs-repository-version-hg 

Command. Not sure what to do with emacs-repository-get-version though.
Maybe I should define a new variable

 emacs-use-hg 

Which per default is nil.

Not sure 


Uwe Brauer 

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Re: emacs-repository-version not defined when cloned with mercurial

[Uwe Brauer]

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>>> "SJ" == Sven Joachim <svenjoac@gmx.de> writes:

> On 2019-08-09 13:24 -0700, Paul Eggert wrote:
>> On 8/9/19 8:40 AM, Uwe Brauer wrote:
>>> Any change to tell emacs to use the mercurial hash tag?
>> 
>> Sorry, it's not clear what you're asking for here. If you'd like to
>> write and debug the feature it sounds like it'd be a good thing to add
>> to Emacs, though I wouldn't expect it to appear unless a
>> Mercurial-using developer takes the initiative to develop it since it
>> should be needed only by developers of Emacs.

> It might actually be a bit confusing to them if mercurial revision IDs
> are included in bug reports, since those do not exist in the git
> repository.  And I have not found a way to get the original git SHA1
> back, at least it is not reported in "hg log --debug".

This is possible 

    1. Short hash: log -r shortHGhash  --template '{gitnode|short}\n'

    2. Long hash: log -r shortHGhash  --template '{gitnode}\n'

Uwe Brauer 

  


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Re: emacs-repository-version not defined when cloned with mercurial

[Stefan Monnier]

> Command. Not sure what to do with emacs-repository-get-version though.
> Maybe I should define a new variable
>
>  emacs-use-hg 
>
> Which per default is nil.

I think catching an error signaled by `git` and then trying `hg` instead
is a better plan.


        Stefan

Re: emacs-repository-version not defined when cloned with mercurial

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Sat, 10 Aug 2019 05:17:15 -0400
> Cc: Uwe Brauer <oub@mat.ucm.es>
> 
> > Command. Not sure what to do with emacs-repository-get-version though.
> > Maybe I should define a new variable
> >
> >  emacs-use-hg 
> >
> > Which per default is nil.
> 
> I think catching an error signaled by `git` and then trying `hg` instead
> is a better plan.

Why not simply ask users who clone into a Mercurial repository to hack
up a 'git' shell script that will do what Emacs expects using
Mercurial?  I mean, this is an unusual situation which we don't have
to support too actively.  The hash is only important when reporting
bugs.  I find the idea of trying yet another shell command, which
might not exist exactly like the first one, just to support such
unusual use cases, a bit gross for my liking.

Re: emacs-repository-version not defined when cloned with mercurial

[Uwe Brauer]

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>>> "EZ" == Eli Zaretskii <eliz@gnu.org> writes:

   >> From: Stefan Monnier <monnier@iro.umontreal.ca>
   >> Date: Sat, 10 Aug 2019 05:17:15 -0400
   >> Cc: Uwe Brauer <oub@mat.ucm.es>
   >> 
   >> > Command. Not sure what to do with emacs-repository-get-version though.
   >> > Maybe I should define a new variable
   >> >
   >> >  emacs-use-hg 
   >> >
   >> > Which per default is nil.
   >> 
   >> I think catching an error signaled by `git` and then trying `hg` instead
   >> is a better plan.

   > Why not simply ask users who clone into a Mercurial repository to hack
   > up a 'git' shell script that will do what Emacs expects using
   > Mercurial?  I mean, this is an unusual situation which we don't have
   > to support too actively.  The hash is only important when reporting
   > bugs.  

I am not sure I understand your proposal.
I am currently compiling GNU emacs for a commit which 
corresponds to the git hash 
1d75604eaded6a8482d28d57bc8e6a4d99d5caee 

In my mercurial clone this is hash
48e6ea8e6e9f08075949468971312b4c607eb291

Mercurial can without problems translate between both hashes.

However suppose I run the compiled version for a while (and suppose I
even have deleted the cloned mercurial repository) and want to
report a bug, then I don't know for which mercurial I compiled that
version, and I cannot calculate the corresponding git hash.

This is why I try to have a function which would tell me the mercurial
hash.

What is your proposal?


I have to admit that I don't understand who currently emacs is
calculating the git hash. 

I see that it uses shell command 

 git rev-parse HEAD

But where and for which repository.

How can I debug emacs-repository-version?

I am asking this, since my generalization for mercurial did not work


(defun emacs-repository-version-hg (dir)
  "Ask git itself for the version information for directory DIR."
  (message "Waiting for git...")
  (with-temp-buffer
    (let ((default-directory (file-name-as-directory dir)))
      (and (eq 0
	       (with-demoted-errors "Error running hg parent --template: %S"
		 (call-process "hg" nil '(t nil) nil "parent" "--template '{node}\n'")))
	   (progn (goto-char (point-min))
		  (looking-at "[0-9a-fA-F]\\{40\\}"))
	   (match-string 0)))))

(defun emacs-repository-version-git (dir)
  "Ask git itself for the version information for directory DIR."
  (message "Waiting for git...")
  (with-temp-buffer
    (let ((default-directory (file-name-as-directory dir)))
      (and (eq 0
	       (with-demoted-errors "Error running git rev-parse: %S"
		 (call-process "git" nil '(t nil) nil "rev-parse" "HEAD")))
	   (progn (goto-char (point-min))
		  (looking-at "[0-9a-fA-F]\\{40\\}"))
	   (match-string 0)))))

(defun emacs-repository-get-version (&optional dir external)
  "Try to return as a string the repository revision of the Emacs sources.
The format of the returned string is dependent on the VCS in use.
Value is nil if the sources do not seem to be under version
control, or if we could not determine the revision.  Note that
this reports on the current state of the sources, which may not
correspond to the running Emacs.

Optional argument DIR is a directory to use instead of `source-directory'.
Optional argument EXTERNAL is ignored."
  (emacs-repository-version-hg (or dir source-directory)))



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Re: emacs-repository-version not defined when cloned with mercurial

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Date: Sat, 10 Aug 2019 12:09:55 +0200
> 
>    > Why not simply ask users who clone into a Mercurial repository to hack
>    > up a 'git' shell script that will do what Emacs expects using
>    > Mercurial?  I mean, this is an unusual situation which we don't have
>    > to support too actively.  The hash is only important when reporting
>    > bugs.  
> 
> I am not sure I understand your proposal.

The prop[osal is to have a script called 'git' which would call hg to
return the Git hash of a repository cloned with hg.  Then Emacs will
get what it wants what it calls "git rev-parse".

> Mercurial can without problems translate between both hashes.
> 
> However suppose I run the compiled version for a while (and suppose I
> even have deleted the cloned mercurial repository) and want to
> report a bug, then I don't know for which mercurial I compiled that
> version, and I cannot calculate the corresponding git hash.

AFAIR, the hash is computed when Emacs is built, and is recorded in
the built Emacs.  It cannot be calculated after the build.

Re: emacs-repository-version not defined when cloned with mercurial

[Uwe Brauer]

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   > The prop[osal is to have 

Sorry I am still confused. Do I understand that correctly
   > a script called 'git' which would call hg to
   > return the Git hash of a repository cloned with hg.  


    1. You want a (shell) script called git, although there is an
       executable called git?
   > Then Emacs will
   > get what it wants what it calls "git rev-parse".


    2. I don't see how, as I said 

 git rev-parse HEAD == hg parent  --template '{node}\n'

    so even with the «definition»
    alias git "hg parent  --template     '{node}\n'"
    would not work. 

I am sure I misunderstood you, but I would appreciate any clarification 


   > AFAIR, the hash is computed when Emacs is built, and is recorded in
   > the built Emacs.  It cannot be calculated after the build.


That makes a lot of sense. 

It think I know where is my mistake, however I am not sure how to solve
it.

The git command to obtain the hash is as I said 

git rev-parse HEAD

And it is implemented as 

(call-process "git" nil '(t nil) nil "rev-parse" "HEAD")

and when I execute the call in the git repository it gives me the
correct hash.

The mercurial command is a bit more complicated 

hg parents --template '{node}\n'

(And maybe the ' cause some problem.

I used 
(call-process "hg" nil '(t nil) nil "parent" "--template '{node}\n'")

but when I execute (via M-:) then it does not give the correct answer.
It gives 

hg parents [-r REV] [FILE]

show the parents of the working directory or revision (DEPRECATED)

options:

 -r --rev REV           show parents of the specified revision
 -T --template TEMPLATE display with template
    --mq                operate on patch repository

(use 'hg parents -h' to show more help)

Which is clear sign that not all the parameters were passed correctly. 

Could somebody please tell me how the 
call 
hg parents --template '{node}\n'

Is correctly translated to the 

call-process 

Thanks

Uwe Brauer 

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Re: emacs-repository-version not defined when cloned with mercurial

[Eli Zaretskii]

> From: Uwe Brauer <oub@mat.ucm.es>
> Date: Sat, 10 Aug 2019 15:12:18 +0200
> 
> I used 
> (call-process "hg" nil '(t nil) nil "parent" "--template '{node}\n'")
> 
> but when I execute (via M-:) then it does not give the correct answer.
> It gives 
> 
> hg parents [-r REV] [FILE]
> 
> show the parents of the working directory or revision (DEPRECATED)
> 
> options:
> 
>  -r --rev REV           show parents of the specified revision
>  -T --template TEMPLATE display with template
>     --mq                operate on patch repository
> 
> (use 'hg parents -h' to show more help)
> 
> Which is clear sign that not all the parameters were passed correctly. 

You need to make each command-line argument a separate string, I
think:

  (call-process "hg" nil '(t nil) nil "parents" "--template" "{node}\n")

Re: emacs-repository-version not defined when cloned with mercurial

[Uwe Brauer]

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   > You need to make each command-line argument a separate string, I
   > think:

   >   (call-process "hg" nil '(t nil) nil "parents" "--template" "{node}\n")


Ah, thanks very much: now it works as expected. 

I am not sure how to proceed. I could send a patch, but from the
discussion I got the impression that it might not be needed since it is
a rare corner case.


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