ext/iconv/.libs/iconv.o: In function `php_iconv_stream_filter_ctor':
/ext/iconv/iconv.c:2491: undefined reference to `libiconv_open'
collect2: ld returned 1 exit status
make: *** [sapi/cli/php] Error 1

解决方法：

使用：make ZEND_EXTRA_LIBS='-liconv' 

或者： vim Makefile

添加：-lcrypt

然后重新编译