We are linking against PulseAudio’s libpulse,
which adds its soname to DT_NEEDED but we are expecting
to actually use our shim with the same soname from LIBPULSE_PATH
(forced by adding the path to LD_LIBRARY_PATH).
Package managers like Nix will detect that we are linking against
PulseAudio’s libpulse and mark it as a runtime dependency by adding
its path to DT_RUNPATH entry so that it can be easily found
by the loader. LD_LIBRARY_PATH will take precedence but it will still
pull PulseAudio into the system’s closure.
The metadata is implemented by the session manager and it can decide
what to do when the defaults change. It can also choose to save
(some of) the metadata to a database.
The metadata is also shared between applications so that changes can
be picked up immediately.
On GNU/Linux systems, the literal string '${LIB}' in dynamic linker
paths expands to "lib", a biarch libQUAL directory such as "lib64", or
a Debian-style multiarch directory such as "lib/x86_64-linux-gnu".
If we're installing libraries to such a directory, and we have both
word-sizes' compatibility libraries available, then pw-pulse can
use LD_LIBRARY_PATH='/usr/${LIB}/pipewire-0.3/pulse' to make both
i386 and x86_64 programs load the correct version.
Signed-off-by: Simon McVittie <smcv@debian.org>
Don't use a special name for the replacement libraries but install
them into the modules directory by default. Add an option to install
them into another location.
This way, we don't need to set up symlinks in development, distros can
choose to install them where they want and/or we can use symlinks or
LD_LIBRARY path to select the replacement versions.
