On Ubuntu 16.04 Xenial, python-rospkg now depends on non-exsting python-distro

[ANogin]

$ docker pull ubuntu:16.04
[...]
$ docker run -it ubuntu:16.04
# echo 'deb http://packages.ros.org/ros/ubuntu xenial main'  > /etc/apt/sources.list.d/ros-latest.list
# apt-key adv --keyserver hkp://ha.pool.sks-keyservers.net:80 --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
[...]
# apt-get -y update
[...]
# apt-get -y install python-rospkg-modules
[...]
The following packages have unmet dependencies:
 python-rospkg-modules : Depends: python-distro but it is not installable
E: Unable to correct problems, you have held broken packages.

[mikepurvis]

Looks like it's used only conditionally with a fallback:

rospkg/src/rospkg/os_detect.py

Lines 39 to 43 in 9956e80

	# to be removed after Ubuntu Xenial is out of support
	try:
	import platform as distro
	except ImportError:
	import distro

So there should be logic in the setup.py to exclude the dependency from systems which don't have it (although perhaps only in the stdeb case, since maybe you would still want it when installing these tools in a virtualenv).

[ANogin]

Looks like it's used only conditionally with a fallback:

rospkg/src/rospkg/os_detect.py

Lines 39 to 43 in 9956e80

	# to be removed after Ubuntu Xenial is out of support
	try:
	import platform as distro
	except ImportError:
	import distro

So there should be logic in the setup.py to exclude the dependency from systems which don't have it (although perhaps only in the stdeb case, since maybe you would still want it when installing these tools in a virtualenv).

That run-time logic is only helpful once you manage to actually install ROS - the issue I am having is with install-time dependencies.

[dirk-thomas]

@ANogin Thank you for reporting this quickly.

[mikepurvis]

Thanks for the quick fix. 🎉