Bug 579156 – sci-libs/scikits_image-0.12.3 should conditionally depend on dev-python/dask

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Alexander Sergeyev 2016-04-06 12:47:47 UTC]

The update of the scikits_image from version 0.11.3 to 0.12.3 comes along with a wave of new dependencies (56 atoms):

dev-libs/libsodium-1.0.10 dev-python/pyasn1-0.1.9 dev-python/py-1.4.31 dev-python/greenlet-0.4.9 dev-python/zope-interface-4.1.3 dev-python/toolz-0.7.4 dev-python/cloudpickle-0.2.1 dev-python/locket-0.2.0 dev-python/abstract_rendering-0.5.1 dev-python/colorama-0.3.7 dev-python/redis-py-2.10.5 net-libs/zeromq-4.1.4 net-dns/c-ares-1.11.0 dev-python/ply-3.8 dev-python/markupsafe-0.23 dev-python/itsdangerous-0.24 dev-python/blinker-1.4 dev-python/simplejson-3.8.2 dev-python/idna-2.1 dev-python/enum34-1.1.2 dev-python/backports-1.0 dev-python/PySocks-1.5.6 dev-python/ipaddress-1.0.16 dev-python/singledispatch-3.4.0.3-r1 dev-python/futures-3.0.5 dev-python/backports-abc-0.4 virtual/python-asyncio-0 dev-python/backports-ssl-match-hostname-3.5.0.1-r1 dev-python/werkzeug-0.11.5 dev-python/jinja-2.8 dev-python/partd-0.3.2 dev-python/pycparser-2.14 dev-python/pyasn1-modules-0.0.8 dev-python/attrs-15.2.0 virtual/python-ipaddress-1.0 virtual/python-singledispatch-0 virtual/python-futures-0 virtual/python-backports_abc-0 virtual/python-greenlet-1.0 dev-python/cffi-1.5.2 dev-python/websocket-client-0.35.0 dev-python/flask-0.10.1-r2 dev-python/gevent-1.1.1 dev-python/pyzmq-15.2.0 dev-python/cryptography-1.3.1 dev-python/pyopenssl-16.0.0 dev-python/ndg-httpsclient-0.4.0 dev-python/service_identity-16.0.0 dev-python/twisted-core-15.2.1 dev-python/urllib3-1.14 dev-python/requests-2.9.1-r2 dev-python/twisted-web-15.2.1 dev-python/twisted-names-15.2.1 www-servers/tornado-4.3 dev-python/bokeh-0.11.1 dev-python/dask-0.8.1

Note that the list even includes a web-server. All of those packages are transitive dependencies for a single package (dev-python/dask) -- and it is marked as an optional (see here: http://scikit-image.org/docs/dev/install.html), I quote:
"You can use this scikit with the basic requirements listed above, but some functionality is only available with the following installed: dask[array] >= 0.5.0 -- for parallel computation using skimage.util.apply_parallel".

To be more precise, the dask module is imported in skimage/util/apply_parallel.py *inside* "apply_parallel" function, so an import error is only possible when this function is used. And it makes no sense to merge all the additional packages for the single function which could be not needed after all.

So, it would be great to remove hard dev-python/dask dependency and announce an optional one as it was done for dev-python/pygtk and dev-python/astropy in the same ebuild (scikits_image-0.12.3). Maybe a separate "dask" use-flag would be more appropriate.

[Comment 1 Sébastien Fabbro (RETIRED) 2016-04-07 15:54:33 UTC]

commit 31b247eaf817108bb5ad46f455ac59d0dcf45b82
Author: Sébastien Fabbro <[e-mail]>
Date:   Wed Apr 6 23:43:54 2016 +0000

    sci-libs/scikits_image: move heavy dask dependency to optfeature
    
    Gentoo-Bug: https://bugs.gentoo.org/show_bug.cgi?id=579156