As development continues, there sometimes arises the need for additional packages to be installed in order to run the newest version. It is the same case for rsyslog. Since version 6.6.0 there is a requirement for json-c to be installed. For debian 6, there are packages available via package managers for easy installation. So there is no problem. For debian 5, the package repositories are unavailable and there is no .deb for json-c delivered on the disc. But without json-c, there is no chance to even install a current rsyslog on debian 5.
Gladly, there are other means to install json-c. There are tarballs available at
Unpack the tarball and install it with:
./configure --prefix=/usr make make install
Unfortunately, make install seems not to copy all the necessary files to correct destination. You still have to manually copy a single file. Do the following:
cp some/directory/json-c-0.10/json_object_iterator.h /usr/include/json/
Now you are all set up to install rsyslog 6.6.0 or 7.2.0 on a debian 5 system. If other packages are still missing (like bison), they are available as package on the disc.