Packages using CMake often use file(GLOB ...) to retrieve a list of
source files. As this is based on readdir(), the resulting file list
is unsorted. A common use case is to pass this list directly to
add_executable or add_library. But as the order is unpredictable, the
binaries are not reproducible (because the order in which the objects
are linked will vary).
See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=824263
