Re: gnu: python-pytest: Update to 5.2.1.

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hello Tanguy,

Tanguy Le Carrour <tanguy@bioneland.org> writes:

> Hi Guix!
>
> I'm working on updating python-pytest and… not everything is going as
> smoothly as I was expecting! :-(
>
> Pytest 5.2.1 depends on Pluggy >=0.12.0… which depends on
> importlib-metadata. But when I had the latter as a propagated-input to
> python-pluggy, then `guix build` gets stuck.
>
>     diff --git a/gnu/packages/python-xyz.scm b/gnu/packages/python-xyz.scm
>     index a7f83dcd31..ab80cdebf9 100644
>     --- a/gnu/packages/python-xyz.scm
>     +++ b/gnu/packages/python-xyz.scm
>     @@ -8914,17 +8914,19 @@ library as well as on the command line.")
>      (define-public python-pluggy
>        (package
>         (name "python-pluggy")
>     -   (version "0.11.0")
>     +   (version "0.13.0")
>         (source
>          (origin
>           (method url-fetch)
>           (uri (pypi-uri "pluggy" version))
>           (sha256
>            (base32
>     -       "10511a54dvafw1jrk75mrhml53c7b7w4yaw7241696lc2hfvr895"))))
>     +       "0d4gsvb4kjqhiqqi4bbsdp7s1xlyl5phibcw1q1mrpd65xia2pzs"))))
>         (build-system python-build-system)
>         (native-inputs
>          `(("python-setuptools-scm" ,python-setuptools-scm)))
>     +   (propagated-inputs
>     +    `(("python-importlib-metadata" ,python-importlib-metadata)))
>         (synopsis "Plugin and hook calling mechanism for Python")
>         (description "Pluggy is an extraction of the plugin manager as used by
>      Pytest but stripped of Pytest specific details.")
>
> The problem seems to be that python-importlib-metadata's dependency graph
> contains… python-pluggy!
>
> How am I supposed to fix this chicken and egg situation?! Is this
> something that should be notified to upstream?!
>
> Regards

I think I had told you this over IRC, but for the record: Python 3.8
will include importlib-metadata in its core libraries, so after we move
to it on core-updates the chicken and egg situation will be no more.

Maxim