[JoshTriplett]

With current Debian, you don't need to do anything at all, and in particular you should not pass --dbg-package. Instead, dh_strip will automatically create a -dbgsym package containing detached debug symbols, if your package contains a library or binary.

Also, make sure that you build with debug symbols enabled in the first place; the default CFLAGS should do that.

[rkv]

Sorry, I'm not asking about current Debian. In your previous comment you mention that the symbol packages are not new. I'm wondering how people have been creating them on Debian 8.