编译gimp2.8以及gegl时找不到libbabl-0.1.so.0的问题

在编译gimp2.8时要用到gegl，在编译gegl时出现下面的错误：

--[Updating sample compositions]--
./clones.xml
/home/mn/download/gegl-0.2.0/bin/.libs/lt-gegl: error while loading shared libraries: libbabl-0.1.so.0: cannot open shared object file: No such file or directory
make[5]: *** [clones.png] 错误 127
./OpenRaster-00.xml
/home/mn/download/gegl-0.2.0/bin/.libs/lt-gegl: error while loading shared libraries: libbabl-0.1.so.0: cannot open shared object file: No such file or directory
make[5]: *** [OpenRaster-00.png] 错误 127
./OpenRaster-01.xml
/home/mn/download/gegl-0.2.0/bin/.libs/lt-gegl: error while loading shared libraries: libbabl-0.1.so.0: cannot open shared object file: No such file or directory
make[5]: *** [OpenRaster-01.png] 错误 127
./OpenRaster-04.xml
/home/mn/download/gegl-0.2.0/bin/.libs/lt-gegl: error while loading shared libraries: libbabl-0.1.so.0: cannot open shared object file: No such file or directory
make[5]: *** [OpenRaster-04.png] 错误 127
make[4]: *** [images.stamp] 错误 2
make[4]:正在离开目录 `/home/mn/download/gegl-0.2.0/docs/gallery'
make[3]: *** [all-recursive] 错误 1
make[3]:正在离开目录 `/home/mn/download/gegl-0.2.0/docs/gallery'
make[2]: *** [all-recursive] 错误 1
make[2]:正在离开目录 `/home/mn/download/gegl-0.2.0/docs'
make[1]: *** [all-recursive] 错误 1
make[1]:正在离开目录 `/home/mn/download/gegl-0.2.0'
make: *** [all] 错误 2

可以看到错误提示为找不到共享库  libbabl-0.1.so.0

该共享库在安装babl时已经被安装到了目录/usr/local/lib中，共享库必须包含在配置文件/etc/ld.so.conf.d中才能被找到。配置文件/etc/ld.so.conf.d中的内容为：

include /etc/ld.so.conf.d/*.conf

查找目录/etc/ld.so.conf.d，可以看到目录/usr/local/lib已经包含在文件libc.conf中了。

然后，也是做重要的要运行命令ldconfig加载动态库。

ldconfig通常在系统启动时运行,而当用户安装了一个新的动态链接库时,就需要手工运行这个命令.