Internal symbols are added to the dynamic library. This could make automatic checking tools believe we make ABI changes, when the changes are actually only internal.

Additionally people could try to use these internal symbols, which would obviously break when we change them.

There is a patch added to the openSUSE package for quite some time already, but it was never reported upstream and also not written in a way to apply "upstream":
https://build.opensuse.org/package/view_file?expand=1&file=libdiscid-visibility.patch&package=libdiscid&project=multimedia%3Alibs