Error: Invalid formula

[insolera]

system: macOS High Sierra 10.13.3
ruby: ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin16]
i got this error:

Cloning into '/usr/local/Homebrew/Library/Taps/bramstein/homebrew-webfonttools'...
remote: Counting objects: 11, done.
remote: Compressing objects: 100% (11/11), done.
remote: Total 11 (delta 0), reused 5 (delta 0), pack-reused 0
Unpacking objects: 100% (11/11), done.
Error: Invalid formula: /usr/local/Homebrew/Library/Taps/bramstein/homebrew-webfonttools/sfntly.rb
Calling 'depends_on :ant' is disabled!
Use 'depends_on "ant"' instead.
/usr/local/Homebrew/Library/Taps/bramstein/homebrew-webfonttools/sfntly.rb:7:in `class:Sfntly'
Please report this to the bramstein/webfonttools tap!
Or, even better, submit a PR to fix it!

================

Any help?

[filoxo]

This issue stems from the homebrew-webfonttools project, and has an open pull request to fix it bramstein/homebrew-webfonttools#21

Who knows when it'll be fixed, but here's my temporary solution.

1. cd /usr/local/Homebrew/Library/Taps
2. git clone https://github.com/bramstein/homebrew-webfonttools.git ./bramstein/homebrew-webfonttools
3. Modify sfntly.rb to fix the syntax error like in the above PR
4. brew tap bramstein/webfonttools