mono-3.4.0 源码安装时出现的问题 [do-install] Error 2 [install-pcl-targets] Er

Mono 3.4修复了很多bug，继续加强稳定性和性能（其实Mono 3.2。8 已经很稳定，性能也很好了），但是从http://download.mono-project.com/sources/mono/ 下载官方提供的源码安装Mono3.4 出现如下错误：

/usr/bin/install: cannot stat `targets/Microsoft.Portable.Common.targets': No such file or directory
make[7]: *** [install-pcl-targets] Error 1
make[7]: Leaving directory `/usr/local/files/mono-3.4.0/mcs/tools/xbuild'
make[6]: *** [do-install] Error 2
make[6]: Leaving directory `/usr/local/files/mono-3.4.0/mcs/tools/xbuild'
make[5]: *** [install-recursive] Error 1
make[5]: Leaving directory `/usr/local/files/mono-3.4.0/mcs/tools'
make[4]: *** [install-recursive] Error 1
make[4]: Leaving directory `/usr/local/files/mono-3.4.0/mcs'
make[3]: *** [profile-do--net_2_0--install] Error 2
make[3]: Leaving directory `/usr/local/files/mono-3.4.0/mcs'
make[2]: *** [profiles-do--install] Error 2
make[2]: Leaving directory `/usr/local/files/mono-3.4.0/mcs'
make[1]: *** [install-exec] Error 2
make[1]: Leaving directory `/usr/local/files/mono-3.4.0/runtime'
make: *** [install-recursive] Error 1