Nix flake build fails - missing cava

[ipsavitsky]

Running nix flake on latest main will result in the following failure:

❯ nix build
error: builder for '/nix/store/x3bivlxxddlyg27dixnpsswkq6ggkm82-waybar-0.14.0+date=2025-10-19_84ec25b.drv' failed with exit code 1;
       last 25 log lines:
       > Run-time dependency upower-glib found: YES 1.90.6
       > Run-time dependency libpipewire-0.3 found: YES 1.4.7
       > Run-time dependency playerctl found: YES 2.4.1
       > Run-time dependency libpulse found: YES 17.0
       > Run-time dependency libudev found: YES 257
       > Run-time dependency libevdev found: YES 1.13.4
       > Run-time dependency libmpdclient found: YES 2.24
       > Run-time dependency xkbregistry found: YES 1.11.0
       > Run-time dependency jack found: YES 1.9.22
       > Run-time dependency wireplumber-0.5 found: YES 0.5.11
       > Run-time dependency libgps found: YES 3.26.1
       > Library sndio found: YES
       > Checking for function "sioctl_open" with dependency -lsndio: YES
       > Run-time dependency gtk-layer-shell-0 found: YES 0.9.2
       > Run-time dependency systemd found: YES 257
       > Computing int of "__cpp_lib_chrono" : 201907
       > Configuring waybar.service using configuration
       > Run-time dependency cava found: NO (tried pkgconfig and cmake)
       > Looking for a fallback subproject for the dependency cava
       > ERROR: Subproject cava is buildable: NO
       > Message: cava is not found. Building waybar without cava
       >
       > meson.build:500:7: ERROR: Automatic wrap-based subproject downloading is disabled
       >
       > A full log can be found at /build/source/build/meson-logs/meson-log.txt
       For full logs, run:
         nix log /nix/store/x3bivlxxddlyg27dixnpsswkq6ggkm82-waybar-0.14.0+date=2025-10-19_84ec25b.drv

It appears that cava is missing from the build sandbox