When you want to compile the svn version you need wxGTK 2.6. You installed it, but ./configure uses wx-config by default. The problem is that wx-config is symlinked to wxGTK 2.4.2.
You can do one (or more) of these things to solve the problem:
1. change the symlink, so that wx-config points to wx-config-2.6
2. you run ./configure with --with-wx-config=/path/to/wx-config-2.6
3. perhaps removing wxGTK 2.4.2, if also installed could do the same
Daniel