无法cpan安装perl模块-APR请求

我正在做一个恶梦，为一个大型perl应用程序整合一个开发环境，我无法安装这个perl模块：

$ sudo cpanm APR::Request
--> Working on APR::Request
Fetching http://www.cpan.org/authors/id/I/IS/ISAAC/libapreq2-2.13.tar.gz ... OK
Configuring libapreq2-2.13 ... OK
Building and testing libapreq2-2.13 ... FAIL
! Installing APR::Request failed. See /home/lurk21/.cpanm/work/1393021653.19831/build.log for details. Retry with --force to force install it.

/bin/bash ../../libtool --tag=CC   --mode=link gcc  -g -O2 -export-dynamic -module -avoid-version `/home/lurk21/.cpanm/work/1393021304.15288/libapreq2-2.13/apreq2-config --link-libtool --libs`  /usr/local/apache2/lib/libapr-1.la /usr/local/apache2/lib/libaprutil-1.la  -o mod_apreq2.la -rpath `/usr/local/apache2/bin/apxs -q LIBEXECDIR` handle.lo filter.lo  

gcc -shared  .libs/handle.o .libs/filter.o  -Wl,--rpath -Wl,/home/lurk21/.cpanm/work/1393021304.15288/libapreq2-2.13/library/.libs -Wl,--rpath -Wl,/usr/local/apache2/lib -Wl,--rpath -Wl,/usr/local/apache2/lib /home/lurk21/.cpanm/work/1393021304.15288/libapreq2-2.13/library/.libs/libapreq2.so -lrt -lcrypt -lpthread -ldl -lexpat /usr/local/apache2/lib/libapr-1.so /usr/local/apache2/lib/libaprutil-1.so  -Wl,-soname -Wl,mod_apreq2.so -o .libs/mod_apreq2.so

/usr/bin/ld: cannot find -lexpat
collect2: error: ld returned 1 exit status

当然，--原力没有安装它，我想我也不想安装它。奇怪的是，这两个文件都存在：

/usr/local/apache2/lib/libapr-1.so 
/usr/local/apache2/lib/libaprutil-1.so 

我已经安装了libapr：

$ aptitude search libapr | egrep "^i"
i A libapr1                         - Apache Portable Runtime Library           
i A libapr1-dev                     - Apache Portable Runtime Library - Developm
i   libapreq2-3                     - generic Apache request library            
i   libapreq2-dev                   - generic Apache request library - developme
i A libapreq2-doc                   - generic Apache request library - documenta
i A libaprutil1                     - Apache Portable Runtime Utility Library   
i A libaprutil1-dbd-sqlite3         - Apache Portable Runtime Utility Library - 
i A libaprutil1-ldap                - Apache Portable Runtime Utility Library - 

什么提示？

提示是

/usr/bin/ld: cannot find -lexpat

也就是说，您需要安装expat XML解析器库。试一试

sudo apt-get install expat
sudo yum install expat

---

从没听说过那个东西，但我按照你的建议安装了它。不幸的是，这并没有改变这种情况。