undefined method `empty?' for nil:NilClass

[arkrost]

It seems that this commit introduces error.

Please report this bug:
  https://docs.brew.sh/Troubleshooting.html
/usr/local/Homebrew/Library/Taps/robertgzr/homebrew-tap/iosevka.rb:149:in `install'
/usr/local/Homebrew/Library/Homebrew/build.rb:140:in `block (2 levels) in install'
/usr/local/Homebrew/Library/Homebrew/formula.rb:1095:in `block in brew'
/usr/local/Homebrew/Library/Homebrew/formula.rb:1895:in `block (2 levels) in stage'
/usr/local/Homebrew/Library/Homebrew/utils.rb:552:in `with_env'
/usr/local/Homebrew/Library/Homebrew/formula.rb:1894:in `block in stage'
/usr/local/Homebrew/Library/Homebrew/resource.rb:119:in `block in unpack'
/usr/local/Homebrew/Library/Homebrew/extend/fileutils.rb:14:in `block in mktemp'
/usr/local/Homebrew/Library/Homebrew/extend/fileutils.rb:74:in `block in run'
/usr/local/Homebrew/Library/Homebrew/extend/fileutils.rb:74:in `chdir'
/usr/local/Homebrew/Library/Homebrew/extend/fileutils.rb:74:in `run'
/usr/local/Homebrew/Library/Homebrew/extend/fileutils.rb:13:in `mktemp'
/usr/local/Homebrew/Library/Homebrew/resource.rb:114:in `unpack'
/usr/local/Homebrew/Library/Homebrew/resource.rb:92:in `stage'
/usr/local/Homebrew/Library/Homebrew/formula.rb:1872:in `stage'
/usr/local/Homebrew/Library/Homebrew/formula.rb:1090:in `brew'
/usr/local/Homebrew/Library/Homebrew/build.rb:111:in `block in install'
/usr/local/Homebrew/Library/Homebrew/utils.rb:552:in `with_env'
/usr/local/Homebrew/Library/Homebrew/build.rb:108:in `install'
/usr/local/Homebrew/Library/Homebrew/build.rb:189:in `<main>'

[bijn]

Ran into this error as well. Seems like the formula is accessing null variables. In case anyone is having trouble, this seemed to fix it for me:

[cryptism]

@bijn looks good, but shouldn't that second change be preset << ligset unless ligset == nil??