Subversion - Retrieval of mergeinfo unsupported
Solution 1:
It looks like your server version is too old (1.4.2). Your client, svnadmin, and repository are all at least 1.5, which is good, but I think your server itself needs to be at least 1.5 as well to support a "merge --reintegrate"
Solution 2:
It was the mod_dav_svn module that was out of date. I fixed this by running the following:
apt-get -t etch-backports install libapache2-svn
Thanks to the Subversion users mailing list for pin-pointing this.
Thanks,
James.