-The default prefix moved from / to /usr to support installations without
-the historic / vs. /usr split.
+A writable /run directory (tmpfs) is required now for a fully functional
+udev.
+
+The default 'configure' install locations have changed. Packages for systems
+with the historic / vs. /usr split need to be adapted, otherwise udev will
+be installed in /usr and not work properly. Example configuration options are
+in INSTALL.