Expiry of Default Debug Key

Today, when I tried to build and test my new android application on my Samsung Nexus S., a sparking red error popup in my problems window of Eclipse. The error message shows as:

Description ResourcePath LocationType Error generating final archive: 

Debug Certificate expired on 8/10/11 8:48 PMSample_10_3 UnknownAndroid Packaging Problem

I tried to delete this error by press "Delete", but the new error message shows me I don't have the respective .apk file, which caused by failed to build my application.

The problem for these error messages is my default debug key is expired, which demonstrates I have been an Android Developer for One Year. It reminds me the first HelloWorld application I tried with the emulator last year. It's in Bin's Bio-Medical Engineering class. My mind was out of class, which is filled with the question "Why my helloworld application never works." (Actually the reason is I never have the patient for that running out.)  How time flies.

The solution for this problem is: delete the debug.keystore, which is under my ~/.android/ directory. For different OS, the dir might be different.

For reference,
http://developer.android.com/guide/publishing/app-signing.html#debugexpiry