checking for event2/thread.h... no libevent_pthreads required, failing

/**********************************************************************************
 *    checking for event2/thread.h... no libevent_pthreads required, failing
 * 说明：
 *     编译libwebsock，遇到这个问题，差点资料，解决一下，毕竟用起来简单。
 *
 *                                           2017-3-17 深圳 南山平山村 曾剑锋
 *********************************************************************************/

一、参考文档：
    . magent编译报错error: event.h: No such file or directory
        http://blog.csdn.net/vio4677/article/details/48492927

二、编译错误输出：
    zengjf@zengjf:~/zengjf/zengjfos/libwebsock$ ./configure
    checking for a BSD-compatible install... /usr/bin/install -c
    checking whether build environment is sane... yes
    checking for a thread-safe mkdir -p... /bin/mkdir -p
    checking for gawk... no
    checking for mawk... mawk
    checking whether make sets $(MAKE)... yes
    checking whether make supports nested variables... yes
    checking for gcc... gcc
    checking whether the C compiler works... yes
    checking for C compiler default output file name... a.out
    checking for suffix of executables...
    checking whether we are cross compiling... no
    checking for suffix of object files... o
    checking whether we are using the GNU C compiler... yes
    checking whether gcc accepts -g... yes
    checking for gcc option to accept ISO C89... none needed
    checking whether gcc understands -c and -o together... yes
    checking for style of include used by make... GNU
    checking dependency style of gcc... gcc3
    checking build system type... x86_64-unknown-linux-gnu
    checking host system type... x86_64-unknown-linux-gnu
    checking how to print strings... printf
    checking for a sed that does not truncate output... /bin/sed
    checking for grep that handles long lines and -e... /bin/grep
    checking for egrep... /bin/grep -E
    checking for fgrep... /bin/grep -F
    checking for ld used by gcc... /usr/bin/ld
    checking if the linker (/usr/bin/ld) is GNU ld... yes
    checking for BSD- or MS-compatible name lister (nm)... /usr/bin/nm -B
    checking the name lister (/usr/bin/nm -B) interface... BSD nm
    checking whether ln -s works... yes
    checking the maximum length of command line arguments...
    checking how to convert x86_64-unknown-linux-gnu file names to x86_64-unknown-linux-gnu format... func_convert_file_noop
    checking how to convert x86_64-unknown-linux-gnu file names to toolchain format... func_convert_file_noop
    checking for /usr/bin/ld option to reload object files... -r
    checking for objdump... objdump
    checking how to recognize dependent libraries... pass_all
    checking for dlltool... no
    checking how to associate runtime and link libraries... printf %s\n
    checking for ar... ar
    checking for archiver @FILE support... @
    checking for strip... strip
    checking for ranlib... ranlib
    checking command to parse /usr/bin/nm -B output from gcc object... ok
    checking for sysroot... no
    checking for a working dd... /bin/dd
    checking how to truncate binary pipes... /bin/dd bs= count=
    checking for mt... mt
    checking if mt is a manifest tool... no
    checking how to run the C preprocessor... gcc -E
    checking for ANSI C header files... yes
    checking for sys/types.h... yes
    checking for sys/stat.h... yes
    checking for stdlib.h... yes
    checking for string.h... yes
    checking for memory.h... yes
    checking for strings.h... yes
    checking for inttypes.h... yes
    checking for stdint.h... yes
    checking for unistd.h... yes
    checking for dlfcn.h... yes
    checking for objdir... .libs
    checking if gcc supports -fno-rtti -fno-exceptions... no
    checking for gcc option to produce PIC... -fPIC -DPIC
    checking if gcc PIC flag -fPIC -DPIC works... yes
    checking if gcc static flag -static works... yes
    checking if gcc supports -c -o file.o... yes
    checking if gcc supports -c -o file.o... (cached) yes
    checking whether the gcc linker (/usr/bin/ld -m elf_x86_64) supports shared libraries... yes
    checking whether -lc should be explicitly linked in... no
    checking dynamic linker characteristics... GNU/Linux ld.so
    checking how to hardcode library paths into programs... immediate
    checking whether stripping libraries is possible... yes
    checking if libtool supports shared libraries... yes
    checking whether to build shared libraries... yes
    checking whether to build static libraries... no
    checking netdb.h usability... yes
    checking netdb.h presence... yes
    checking for netdb.h... yes
    checking for stdlib.h... (cached) yes
    checking for string.h... (cached) yes
    checking sys/socket.h usability... yes
    checking sys/socket.h presence... yes
    checking for sys/socket.h... yes
    checking for unistd.h... (cached) yes
    checking for size_t... yes
    checking for stdlib.h... (cached) yes
    checking for GNU libc compatible malloc... yes
    checking for stdlib.h... (cached) yes
    checking for GNU libc compatible realloc... yes
    checking for memset... yes
    checking for socket... yes
    checking for strstr... yes
    checking event2/thread.h usability... no
    checking event2/thread.h presence... no
    checking for event2/thread.h... no
    libevent_pthreads required, failing
    zengjf@zengjf:~/zengjf/zengjfos/libwebsock$ 

三、错误原因：
    . 通过在根目录查找thread.h，未找到，说明是因为安装了libevent但是没有安装头文件导致的
    . 重新下载libevent，然后编译安装就OK了
    . http://libevent.org/下载libevent-2.0.22-stable.tar.gz
    . ./configure && make && make install