Stuff I didn't expect I'd had to type today:
$ dpkg-repack dpkg-repack
As the author, you've officially come up with a use for dpkg-repack that I never anticipated. :)
I suggest the option dpkg-repack itself for a future version :-)
And a useful one :) Being able to do that saved my ass yesterday, I don't know if or how I'd have easily fixed my situation otherwise (apt/dpkg upgrade fuckup involving libc6 and kernels that are too old).
Thanks for the software :)
You could be a gcc developer, and build gcc with gcc every time you change anything. Then you build gcc with gcc again, and verify that you get the same bits.