Sources.d.o confirms the mesa package has src/vulkan/runtime/vk_instance.c and it contains calls to enumerate_drm_physical_devices()
https://sources.debian.org/src/mesa/26.0.0-1/src/vulkan/runtime/vk_instance.c#L457
However, codesearc.d.n fails to report any results and exploring via modified, shorter, search terms seems to indicate part of the package may not be indexed.
Sources.d.o confirms the mesa package has
src/vulkan/runtime/vk_instance.cand it contains calls toenumerate_drm_physical_devices()https://sources.debian.org/src/mesa/26.0.0-1/src/vulkan/runtime/vk_instance.c#L457
However, codesearc.d.n fails to report any results and exploring via modified, shorter, search terms seems to indicate part of the package may not be indexed.