multimon-ng fails due to X11 dependency

[yaakov-h]

yaakov@Ilum ~ % brew tap dholm/homebrew-sdr
==> Tapping dholm/sdr
Cloning into '/opt/homebrew/Library/Taps/dholm/homebrew-sdr'...
remote: Enumerating objects: 441, done.
remote: Total 441 (delta 0), reused 0 (delta 0), pack-reused 441
Receiving objects: 100% (441/441), 120.77 KiB | 3.77 MiB/s, done.
Resolving deltas: 100% (269/269), done.
Error: Invalid formula: /opt/homebrew/Library/Taps/dholm/homebrew-sdr/multimon-ng.rb
multimon-ng: Calling depends_on :x11 is disabled! Use depends_on specific X11 formula(e) instead.
Please report this issue to the dholm/sdr tap (not Homebrew/brew or Homebrew/core), or even better, submit a PR to fix it:
  /opt/homebrew/Library/Taps/dholm/homebrew-sdr/multimon-ng.rb:8

Error: Cannot tap dholm/sdr: invalid syntax in tap!
yaakov@Ilum ~ % 

---

I am running Homebrew 3.0.9 on macOS 11.12.3.

[scottscode]

Received the same error:

brew tap dholm/homebrew-sdr
==> Tapping dholm/sdr
Cloning into '/usr/local/Homebrew/Library/Taps/dholm/homebrew-sdr'...
remote: Enumerating objects: 441, done.
remote: Total 441 (delta 0), reused 0 (delta 0), pack-reused 441
Receiving objects: 100% (441/441), 120.77 KiB | 1.31 MiB/s, done.
Resolving deltas: 100% (269/269), done.
Error: Invalid formula: /usr/local/Homebrew/Library/Taps/dholm/homebrew-sdr/multimon-ng.rb
multimon-ng: Unsupported special dependency :x11
Error: Cannot tap dholm/sdr: invalid syntax in tap!

OSX Catalina 10.15.7

Homebrew 3.4.4
Homebrew/homebrew-core (git revision df796bddb91; last commit 2022-03-30)
Homebrew/homebrew-cask (git revision e01d3af6f8; last commit 2022-03-30)

[ersingencturk]

same here too:

Tapping dholm/sdr
Cloning into '/usr/local/Homebrew/Library/Taps/dholm/homebrew-sdr'...
remote: Enumerating objects: 441, done.
remote: Total 441 (delta 0), reused 0 (delta 0), pack-reused 441
Receiving objects: 100% (441/441), 120.77 KiB | 1.04 MiB/s, done.
Resolving deltas: 100% (269/269), done.
Error: Invalid formula: /usr/local/Homebrew/Library/Taps/dholm/homebrew-sdr/multimon-ng.rb
multimon-ng: Unsupported special dependency :x11
Error: Cannot tap dholm/sdr: invalid syntax in tap!

[0xffset]

x2