我交叉编译libxml2的时候出现：
make[3]: Entering directory `/usr/local/src/libxml2-2.7.2/include/libxml'
make[3]: Nothing to be done for `all'.
make[3]: Leaving directory `/usr/local/src/libxml2-2.7.2/include/libxml'
make[3]: Entering directory `/usr/local/src/libxml2-2.7.2/include'
make[3]: Nothing to be done for `all-am'.
make[3]: Leaving directory `/usr/local/src/libxml2-2.7.2/include'
make[2]: Leaving directory `/usr/local/src/libxml2-2.7.2/include'
之后，在交叉编译php的时候，就出现：
checking whether to enable LIBXML support... yes
checking libxml2 install dir... /usr/local/
checking for xml2-config path... /usr/local//bin/xml2-config
checking whether libxml build works... no
configure: error: build test failed.  Please check the config.log for details.
这个问题怎么解决啊，各位懂的麻烦告诉我一下，谢谢