First; log in as root to do administrative work, instead of screwing around with sudo.
Second; the dependencies for your desired package are not available in Stable. libc6 is one of the system's core components. Since the package you want requires a newer version, you cannot install it. You might be luck enough to find that package in backports, but most likely you only have two options:
1) Upgrade to Testing.
2) Forget about that package.