Oxygen Mono font is no longer considered monospace after updating packages

I’ve been using Oxygen Mono as my monospace font in the kitty terminal emulator, after I failed to get Monaco working (I installed it, but it was not considered monospace by the system). When I updated my packages yesterday, Oxygen Mono stopped working in kitty, and fc-query shows that it doesn’t have a spacing value. kitty wasn’t updated in this batch of updates and the font itself is still recognised by the system and hasn’t moved or been modified. I have no idea what caused this or how to fix it.

Here is my output for inxi -Fazy:

  Kernel: 5.7.12-arch1-1 x86_64 bits: 64 compiler: gcc v: 10.1.0 
  parameters: BOOT_IMAGE=/boot/vmlinuz-linux 
  root=UUID=3ee3ea5d-c1ba-43e1-887b-8ef291ef557e rw quiet apparmor=1 
  security=apparmor udev.log_priority=3 
  Desktop: KDE Plasma 5.19.4 tk: Qt 5.15.0 wm: kwin_x11 dm: SDDM 
  Distro: Manjaro Linux 
  Type: Desktop System: Apple product: iMac13,2 v: 1.0 serial: <filter> 
  Chassis: type: 13 v: Mac-FC02E91DDD3FA6A4 serial: <filter> 
  Mobo: Apple model: Mac-FC02E91DDD3FA6A4 v: iMac13,2 serial: <filter> 
  UEFI: Apple v: date: 04/12/2020 
  Device-1: apple_mfi_fastcharge model: N/A serial: N/A charge: N/A 
  status: N/A 
  Topology: Quad Core model: Intel Core i7-3770 bits: 64 type: MT MCP 
  arch: Ivy Bridge family: 6 model-id: 3A (58) stepping: 9 microcode: 21 
  L2 cache: 8192 KiB 
  flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 54297 
  Speed: 1620 MHz min/max: 1600/3900 MHz Core speeds (MHz): 1: 1596 2: 1597 
  3: 1597 4: 1597 5: 1596 6: 1597 7: 1596 8: 1597 
  Vulnerabilities: Type: itlb_multihit status: KVM: Split huge pages 
  Type: l1tf 
  mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable 
  Type: mds mitigation: Clear CPU buffers; SMT vulnerable 
  Type: meltdown mitigation: PTI 
  Type: spec_store_bypass 
  mitigation: Speculative Store Bypass disabled via prctl and seccomp 
  Type: spectre_v1 
  mitigation: usercopy/swapgs barriers and __user pointer sanitization 
  Type: spectre_v2 mitigation: Full generic retpoline, IBPB: conditional, 
  IBRS_FW, STIBP: conditional, RSB filling 
  Type: srbds status: Vulnerable: No microcode 
  Type: tsx_async_abort status: Not affected 
  Device-1: NVIDIA GK104M [GeForce GTX 680MX] vendor: Apple iMac 13 2 
  driver: nouveau v: kernel bus ID: 01:00.0 chip ID: 10de:11a3 
  Device-2: Apple type: USB driver: uvcvideo bus ID: 1-1.1:3 
  chip ID: 05ac:8511 serial: <filter> 
  Display: x11 server: X.Org 1.20.8 compositor: kwin_x11 driver: modesetting 
  alternate: fbdev,nouveau,nv,vesa display ID: :0 screens: 1 
  Screen-1: 0 s-res: 2560x1440 s-dpi: 96 s-size: 677x381mm (26.7x15.0") 
  s-diag: 777mm (30.6") 
  Monitor-1: DP-1 res: 2560x1440 hz: 60 dpi: 109 size: 597x336mm (23.5x13.2") 
  diag: 685mm (27") 
  OpenGL: renderer: NVE4 v: 4.3 Mesa 20.1.6 direct render: Yes 
  Device-1: Intel 7 Series/C216 Family High Definition Audio 
  driver: snd_hda_intel v: kernel bus ID: 00:1b.0 chip ID: 8086:1e20 
  Device-2: NVIDIA GK104 HDMI Audio vendor: Apple driver: snd_hda_intel 
  v: kernel bus ID: 01:00.1 chip ID: 10de:0e0a 
  Sound Server: ALSA v: k5.7.12-arch1-1 
  Device-1: Broadcom and subsidiaries NetXtreme BCM57766 Gigabit Ethernet PCIe 
  vendor: Apple driver: tg3 v: kernel port: 2000 bus ID: 03:00.0 
  chip ID: 14e4:1686 
  IF: enp3s0f0 state: up speed: 1000 Mbps duplex: full mac: <filter> 
  Device-2: Broadcom and subsidiaries BCM4331 802.11a/b/g/n 
  vendor: Apple AirPort Extreme driver: wl v: kernel modules: bcma port: 2000 
  bus ID: 04:00.0 chip ID: 14e4:4331 
  IF: wlp4s0 state: up mac: <filter> 
  IF-ID-1: enp0s20u1c4i2 state: down mac: <filter> 
  IF-ID-2: vmnet1 state: unknown speed: N/A duplex: N/A mac: <filter> 
  IF-ID-3: vmnet8 state: unknown speed: N/A duplex: N/A mac: <filter> 
  Local Storage: total: 2.73 TiB used: 28.08 GiB (1.0%) 
  SMART Message: Unable to run smartctl. Root privileges required. 
  ID-1: /dev/sda vendor: Apple model: HDD ST3000DM001 size: 2.73 TiB 
  block size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s 
  rotation: 7200 rpm serial: <filter> rev: AQ03 scheme: GPT 
  ID-2: /dev/sdb type: USB vendor: Toshiba model: TransMemory size: 3.75 GiB 
  block size: physical: 512 B logical: 512 B serial: <filter> rev: PMAP 
  scheme: MBR 
  SMART Message: Unknown USB bridge. Flash drive/Unsupported enclosure? 
  ID-1: / raw size: 147.92 GiB size: 144.60 GiB (97.75%) 
  used: 28.03 GiB (19.4%) fs: ext4 dev: /dev/sda6 
  Alert: No Swap data was found. 
  System Temperatures: cpu: 68.0 C mobo: N/A gpu: nouveau temp: 63 C 
  Fan Speeds (RPM): N/A 
  Processes: 306 Uptime: 20h 16m Memory: 15.58 GiB used: 3.50 GiB (22.5%) 
  Init: systemd v: 246 Compilers: gcc: 10.2.0 clang: 10.0.1 Packages: 
  pacman: 1277 lib: 324 flatpak: 0 Shell: Zsh v: 5.8 running in: kitty 
  inxi: 3.1.05 

I know this is just a workaround and not a solution, but I standardised on Envy Code R because it’s a font developed by a coder for coders.

Never had any trouble with that font and it works great in terminals too!