Autotools and CMake uses different version numbering in xmlversion.h(.in)
Looking at the comments in xmlversion.h.in the idea seems to be replace "." (dots) with 0 (zero) and while Cmake follows that pattern Autotools doesn't by not inserting a zero for micro/"patch" version.
#define LIBXML_VERSION 20912 #define LIBXML_VERSION 209013
#define LIBXML_VERSION_STRING "20912" #define LIBXML_VERSION_STRING "209013"
I guess that's a bug due to lack of documentation on how to handle double digits and both should adopt what Autotools does?
Reported here: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=263094