BUILDING_FROM_VCS

[Geert Janssens]

Eric Siegerman <pub08-gnc at davor.org> schreef op 10 maart 2018 20:34:39 CET:
>On Sat, Mar 10, 2018 at 09:00:29AM -0800, John Ralls wrote:
>> One possible solution would be to test the value of `git remote -v 2>
>/dev/null | grep "origin.*(fetch)"`. If it’s either code or the Github
>mirror then we set the version from `git describe`, otherwise it’s the
>${VERSION} as set in CMakeLists.txt.
>
>This seems fragile.  (1) If someone's building from a clone of a clone,
>it will fail.  (2) The remote might not be called "origin" (e.g. I
>typically use "upstream").
>

Good points.

>Here's an idea: add a sentinel file to the git repo, but exclude it
>from the dist tarballs etc.  If the file exists in the source tree,
>you're building from the official git repo or a (possibly indirect)
>clone of same.  If it doesn't exist, you're building from something
>else (and I don't think it matters what variety of something-else --
>tarball, tarball-checked-into-git, etc.) 

Unfortunately it does matter. Github allows you to download any commit as a tarball. That tarball would also include the sentinel...

 The sentinel's content is
>irrelevant (unless for extra certainty you want the git-repo check to
>verify it); it's the file's presence or absence that matters.
>
>This has the advantage of being VCS-agnostic, since it only looks at
>the working tree.
>
>Or the sentinel could always exist, but its contents could provide the
>needed info. E.g. it's in the source tree with (hard-coded and
>git-committed) contents that say basically "I'm from git".  But the
>dist build puts into the tarball a variant that says, "My ultimate
>source is {release 2.7.5|official git commit 123abc|<whatever else
>makes sense>}, but I'm not directly from there".  Not in those exact
>words, obviously.
>
>What makes gnc-version.h and gnc-vcs-info.h unsuitable is that they're
>regenerated on a normal "make all" build, if necessary.  The key would
>be that the sentinel I'm suggesting is only generated at "make dist"
>time:
>- if you're building from an official repo (or clone), the file never
>changes
>  - if you're building from a tarball, the file still never changes
>It only changes at the transition between those two states, i.e. "make
>dist".

Make dist is called all the time by developers to test the creation of a dist tarball, so the info would get updated more frequently then intended. Or it would require manual intervention,  which brings us back at square one. 
>
>> ChangeLog is a bit harder [...] or maybe it should be simply dropped.
>
>That would be unfortunate.  Even though the info is available
>elsewhere, it's good to have it encapsulated with the rest of the
>distribution.
>

Ok, this part isn't decided yet...
>  - Eric

Geert


Sent from my smartphone. Please excuse my brevity.