Ubuntu14.04 installation build-essential failed, how to solve the package dependency problem?

Reading Package List ... Complete
Analyzing Dependency tree for Package
Reading status information ... Complete
Some software packages cannot be installed. If you are using the unstable release, this may be
Because the system is unable to achieve the state you requested. There may be some software that you need in this release
The packages have not been created or they have been removed from the new to (Incoming) directory.
The following information may be helpful in resolving a problem:


The following packages have unsatisfied dependencies:
Build-essential: Dependent: Libc6-dev But it will not be installed or
Libc-dev
Dependent: gcc (>= 4:4.4.3) but it will not be installed
Dependent: g++ (>= 4:4.4.3) but it will not be installed

E: The error cannot be corrected because you require certain packages to remain current, that is, they destroy the dependencies between the software packages.

Add point source First, then sudo apt-get updatethen sudo apt-get install build-essential can solve the problem!

Ubuntu14.04 installation build-essential failed, how to solve the package dependency problem?