I followed the http://libguestfs.org/guestfs-building.1.html to build source.

git clone https://github.com/libguestfs/libguestfs
 cd libguestfs
 ./autogen.sh
 make
I installed the lib I didn't have it and everything is ok untill I enter make

I got error message:
  CCLD     libguestfs.la
ar: `u' modifier ignored since `D' is the default (see `U')
make[3]: Leaving directory '/home/pahome/git/libguestfs/lib'
make[2]: Leaving directory '/home/pahome/git/libguestfs/lib'
Making all in docs
make[2]: Entering directory '/home/pahome/git/libguestfs/docs'
make[2]: Nothing to be done for 'all'.
make[2]: Leaving directory '/home/pahome/git/libguestfs/docs'
Making all in examples
make[2]: Entering directory '/home/pahome/git/libguestfs/examples'
  CCLD     create-disk
../lib/.libs/libguestfs.so: undefined reference to `yajl_tree_free'
../lib/.libs/libguestfs.so: undefined reference to `yajl_tree_parse'
collect2: error: ld returned 1 exit status
Makefile:1926: recipe for target 'create-disk' failed
make[2]: *** [create-disk] Error 1
make[2]: Leaving directory '/home/pahome/git/libguestfs/examples'
Makefile:1975: recipe for target 'all-recursive' failed
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/home/pahome/git/libguestfs'
Makefile:1884: recipe for target 'all'

why is undefined reference to 'yajl_tree_parse', I already install it from https://github.com/lloyd/yajl