Right now, PACKAGE_DEBUG_SPLIT_STYLE can only package source together with debug data (modes debug-file-directory and the default mode) or exclude the source code from packaging (debug-without-src). Please consider adding modes where source code is packaged in a separate package ("-src") instead of getting included in the -dbg package. This may be useful both for the ".debug" and the "debug-file-directory" style. The motivation for that is the observation that installing valgrind installs libc6-dbg = glibc-dbg, which (in the default mode) contains the entire glibc source code. The source code is not needed when using valgrind, only the debug symbols are. But choosing debug-without-src is not a good solution, because packaging source code is useful for other cases.