On Wed, Apr 03, 2019 at 01:36:24PM +0200, Vincent Prince wrote:
> Adrien,
> 
> What I'm not sure to understand is in which case we use "_git.bb" instead
> of having PV in filename.

The PV in filename is just another way for setting PV variable (instead
of setting it inside the recipe). This isn't relevant to what Adrian
requested and I would keep the filename as is.

> If we use a release version, shouldn't we point to
> https://github.com/zeromq/cppzmq/archive/v4.3.0.tar.gz?

Definitely don't use github archives, they are regenerated from time to
time with different checksums, either you can use developer uploaded
tarballs (some projects on github provides them as well) or use git
fetcher with the SRCREV pointing the the tag.

> And if we use git version, shouldn't we specify git commit hash to remove
> any ambiguity between PV and SRCREV?

With git bitbake fetcher (git:// in SRC_URI) you always need to specify
SRCREV, because that's the only thing which defines what "version" of
the source will be fetched.

PV in this case is only to give this SRCREV some human readable (and
sortable) versioning scheme. And that's what users will see when
installing/upgrading the built packages, so it's important to set it
correctly.

+git${SRCPV} in PV is usually used to signify that the SRCREV points to
commit a bit newer than the "base version" in this case 4.3.1 and in
this case this +git${SRCPV} is unnecessary if the SRCREV matches exactly
with 4.3.1 tag.

> Do you know any convention is specified somewhere?

I don't think it's spelled anywhere in wiki.