Subversion 0.28 wants old (0.23) version of neon. Reproducible: Always Steps to Reproduce: 1. emerge neon 0.24 2. 3. I suggest using the --disable-neon-version-check configure option. Use ebuilds' dependency requirements to keep neon updated instead. Svn 0.28 seems to work just fine with neon 0.24
I just committed 0.30.0 that uses 0.24.2, according to the neon website its interface is in flux so we are probably safer by leaving the version check in.