svn: '...' has no ancestry information

subversion (1.6.5) and - depending on it - mr. developer complained about some strange missing ancestry information.

I tried to commit code from this directory tree:

toplevel/ .svn/

... 2ndlevel/ (no .svn here) ... 3rdlevel/ .svn/ code_to_commit

Trying

cd 3rdlevel svn commit -m 'bla'

produced the error

svn: '2ndlevel' has no ancestry information

which I didn't understand, since the 3rdlevel was a check out of it's own, not related to the toplevel.

subversion seems to look up .svn/ directories along the complete absolute path of the directory which is checked in and hasn't recorded that 3rdlevel/ is a "checkout root".

The solution: removing the .svn in the toplevel dir (putting a reasonable one in 2ndlevel by adding it to svn might have worked, too).