CentOS下已经安装了APR，怎么安装SVN时还提示没有？

xender

configure: WARNING: APR not found
The Apache Portable Runtime (APR) library cannot be found.
Please install APR on this system and supply the appropriate
--with-apr option to 'configure'

or

get it with SVN and put it in a subdirectory of this source:

   svn co \
    http://svn.apache.org/repos/asf/apr/apr/branches/1.3.x \
    apr

Run that right here in the top level of the Subversion tree.
Afterwards, run apr/buildconf in that subdirectory and
then run configure again here.

Whichever of the above you do, you probably need to do
something similar for apr-util, either providing both
--with-apr and --with-apr-util to 'configure', or
getting both from SVN with:

   svn co \
    http://svn.apache.org/repos/asf/apr/apr-util/branches/1.3.x \
    apr-util



这是为啥啊？？？