Three pieces: - hack/pkg-config.sh: a pkg-config wrapper that injects the meson build dir's pkgconfig paths, but only for modules our build provides (streamplacedeps, glib/gstreamer families, lpms's libav*). On Linux --libs answers also gain -lm and an old-style rpath to the build dir, so ld resolves transitive .so deps at link time and test binaries run without LD_LIBRARY_PATH. Explicit PKG_CONFIG_PATH still wins, and everything else passes through untouched. - make dev-setup now registers the wrapper via 'go env -w PKG_CONFIG=...', which Go persists in its own per-user config -- no shell env needed, and gopls picks it up too. - streamplacedeps.pc gains -Wl,-rpath,${libdir} -Wl,--disable-new-dtags on Linux shared builds; DT_RPATH (unlike DT_RUNPATH) also covers transitive loads like libgobject -> libffi and libavcodec -> libswresample, whose meson-built libraries carry no rpath. Note: a build dir produced inside a container (prefix=/app) bakes wrong paths into every .pc file; rerun 'make dev-setup' natively after using one. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>