Homebrew tap not working on Linux

[johnsonjh]

brew tap output:

 » brew tap keys-pub/tap                     

==> Tapping keys-pub/tap
Cloning into '/home/linuxbrew/.linuxbrew/Homebrew/Library/Taps/keys-pub/homebrew-tap'...
remote: Enumerating objects: 385, done.
remote: Counting objects: 100% (146/146), done.
remote: Compressing objects: 100% (120/120), done.
remote: Total 385 (delta 67), reused 18 (delta 9), pack-reused 239
Receiving objects: 100% (385/385), 45.20 KiB | 925.00 KiB/s, done.
Resolving deltas: 100% (187/187), done.

Error: Invalid formula: /home/linuxbrew/.linuxbrew/Homebrew/Library/Taps/keys-pub/homebrew-tap/keys.rb
formulae require at least a URL

brew config:

 » brew config

HOMEBREW_VERSION: 3.2.0
ORIGIN: https://github.com/Homebrew/brew
HEAD: 09f7bc27a99469cf947431df4754737dfbadb31d
Last commit: 13 days ago
Core tap ORIGIN: https://github.com/Homebrew/linuxbrew-core
Core tap HEAD: 4ccfbea4752d145c46c2bab305f5468ac36f3e0a
Core tap last commit: 2 hours ago
Core tap branch: master
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: :0
HOMEBREW_EDITOR: /opt/nvim/bin/nvim
HOMEBREW_MAKE_JOBS: 12
HOMEBREW_NO_ANALYTICS: set
Homebrew Ruby: 2.6.3 => /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/2.6.3_2/bin/ruby
CPU: dodeca-core 64-bit skylake
Clang: 12.0.0 build (parse error)
Git: 2.31.1 => /bin/git
Curl: 7.76.1 => /usr/bin/curl
Kernel: Linux 5.12.7-300.fc34.x86_64 x86_64 GNU/Linux
OS: Fedora release 34 (Thirty Four) (ThirtyFour)
Host glibc: 2.33
/usr/bin/gcc: 11.1.1
/usr/bin/ruby: 3.0.1
glibc: N/A
gcc@5: N/A
xorg: N/A

[gabriel]

I've only ever tested the homebrew setup on macOS.