20. February 2008
As I am usually far to lazy to RTFM I had to learn how to add externals definition to subversion the hard way. But as other might probably need it, too, here is how it works (mind the dot at the end…):
svn propset svn:externals "<directory name> -r<revision> http://svn.gnome.org/svn/yourmodule/trunk/your_directory" .
The problem is that after that command it will not work because you have to commit the property change first:
svn commit -m "Changed external property"
So here is the final example:
svn propset svn:externals "eggtoolpalette -r853 http://svn.gnome.org/svn/libegg/trunk/libegg/toolpalette/" .
svn commit -m "Added eggtoolpalette"
And now you will have eggtoolpalette revision 853 in your tree. Thanks to herzi for helping me solving this problem on IRC.