Problem to start roscore on ARM + Ubuntu 12.04

edit

Hi there,

I installed ros fuerte from source on a new installation of Ubuntu 12.04. When I want to run roscore i get following failure message:

 ... logging to /home/panda/.ros/log/4b069fea-efbf-11e1-b011-2e607c264e01/roslaunch-panda-1813.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

Traceback (most recent call last):
  File "/opt/ros/fuerte/bin/rosversion", line 5, in <module>
    pkg_resources.run_script('rospkg==1.0.6', 'rosversion')
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 499, in run_script
    self.require(requires)[0].run_script(script_name, ns)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1229, in run_script
    raise ResolutionError("No script named %r" % script_name)
pkg_resources.ResolutionError: No script named 'rosversion'
Invalid <param> tag: Cannot load command parameter [rosversion]: command [rosversion ros] returned with code [1].

Param xml is <param command="rosversion ros" name="rosversion"/>

I saw that there was already a question regarding to this kind of failure. So I deleted all rospkg regarding folders under /usr/local/lib/python2.7/dist-packages/ and used

 $sudo easy_install -U rospkg

Unfortunately, I got a different failure msgs then:

 ... logging to /home/panda/.ros/log/e6c9fbac-efbf-11e1-8192-2e607c264e01/roslaunch-panda-1830.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

Unable to contact my own server at [http://panda:60413/].
This usually means that the network is not configured properly.

A common cause is that the machine cannot ping itself.  Please check
for errors by running:

        ping panda

For more tips, please see

        http://www.ros.org/wiki/ROS/NetworkSetup

Which is really weird because i can ping myself without a problem. I deleted all rospkg folders again and used to get back to the old setup.

$sudo pip install -U rospkg

there was a interesting output while installing

Installing collected packages: rospkg
  Running setup.py install for rospkg
    changing mode of build/scripts-2.7/rosversion from 644 to 755

So a ROS-Version must be set somewhere.

the output from $roswtf ist

No package or stack in context
================================================================================
Static checks summary:

Found 1 error(s).

ERROR Not all paths in ROS_PACKAGE_PATH [/opt/ros/fuerte/share:/opt/ros/fuerte/stacks] point to an existing directory:
 * /opt/ros/fuerte/stacks

================================================================================

ROS Master does not appear to be running.
Online graph checks will not be run.
ROS_MASTER_URI is [http://localhost:11311]

I appreciate any kind of suggestions.

Edit:

Lorenz answer is the solution to the problem. I used $ sudo easy_install rospkg and then added

export ROS_HOSTNAME=localhost  
export ROS_MASTER_URI=http://localhost:11311

to my .bashrc

There is now a failure msgs about

Exception AttributeError: AttributeError("'_DummyThread' object has no attribute '_Thread__block'",) in <module 'threading' from '/usr/lib/python2.7/threading.pyc'> ignored

but this shouldn't be an issue. (reference)