gnu: trytond: Fix import of trytond modules.

For adding modules, trytond uses entry-points, anyhow relying on the
modules being named "trytond.modules.xxx" and being placed in the same
filesystem path as "trytond.modules".

The package "trytond.modules" is not a namespace module, anyhow trytond
modules must be sub-modules of "trytond.modules". This works well if all
packages are installed into the same filesystem path "…/trytond/modules":
The Python importer will find all sub_modules at this place.

Anyhow, in Guix, modules don't share the same filesystem path and the
Python importer will not find them.

Solution is to add all trytond module's locations to
"trytond.modules._path__". This will make "trytond.module" behave much
like a namespace module and the importer pick up the module.

* gnu/packages/patches/trytond-add-egg-modules-to-path.patch: New file.
* gnu/packages/tryton.scm (trytond): Use it.
* gnu/local.mk (dist_patch_DATA): Add it

1 files changed, 2 insertions, 1 deletions

diff --git a/gnu/packages/tryton.scm b/gnu/packages/tryton.scm
index 6ba7539b4a..0bd5ffcd5b 100644
--- a/gnu/packages/tryton.scm
+++ b/gnu/packages/tryton.scm
@@ -48,7 +48,8 @@
        (method url-fetch)
        (uri (pypi-uri "trytond" version))
        (sha256
-        (base32 "1jp5cadqpwkcnml8r1hj6aak5kc8an2d5ai62p96x77nn0dp3ny4"))))
+        (base32 "1jp5cadqpwkcnml8r1hj6aak5kc8an2d5ai62p96x77nn0dp3ny4"))
+       (patches (search-patches "trytond-add-egg-modules-to-path.patch"))))
     (build-system python-build-system)
     (propagated-inputs
      (list python-dateutil