Steam on my system is stuck repeatedly trying to update "Proton 9.0" and failing with just the error message "content unavailable" in the downloads view. Everything else seems to be working fine, and I can't find anything relevant from a web search, so I'm now wondering whether this caused by something NixOS specific. When I run Steam from the terminal, there's just this usual noise, and nothing different when the download fails.

pressure-vessel-wrap[423347]: W: Found more than one possible libdrm data directory from provider
pressure-vessel-wrap[423347]: W: "run/opengl-driver-32/share/drirc.d" is unlikely to appear in "/run/host"
pressure-vessel-wrap[423347]: W: "run/opengl-driver/share/drirc.d" is unlikely to appear in "/run/host"
ERROR: ld.so: object '/nix/store/50qmylmifc0naz9iqd9ck1rw43jnz2j5-extest-1.0.2/lib/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/nix/store/50qmylmifc0naz9iqd9ck1rw43jnz2j5-extest-1.0.2/lib/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/nix/store/50qmylmifc0naz9iqd9ck1rw43jnz2j5-extest-1.0.2/lib/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/nix/store/50qmylmifc0naz9iqd9ck1rw43jnz2j5-extest-1.0.2/lib/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
ERROR: ld.so: object '/nix/store/50qmylmifc0naz9iqd9ck1rw43jnz2j5-extest-1.0.2/lib/libextest.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.