invalid syntax in tap! - homebrew ERROR

[uglygus]

$brew -v
Homebrew 1.1.13
Homebrew/homebrew-core (git revision e0ec3; last commit 2017-04-17)

$uname -a
Darwin vpa-tbatters-mb 16.5.0 Darwin Kernel Version 16.5.0: Fri Mar 3 16:52:33 PST 2017; root:xnu-3789.51.2~3/RELEASE_X86_64 x86_64

$brew tap KeckCAVES/keckcaves
Updating Homebrew...
==> Tapping keckcaves/keckcaves
Cloning into '/Users/tbatters/homebrew/Library/Taps/keckcaves/homebrew-keckcaves'...
remote: Counting objects: 9, done.
remote: Compressing objects: 100% (8/8), done.
remote: Total 9 (delta 3), reused 4 (delta 1), pack-reused 0
Unpacking objects: 100% (9/9), done.
Error: Invalid formula: /Users/tbatters/homebrew/Library/Taps/keckcaves/homebrew-keckcaves/vrui-examples.rb
Calling Formula.sha1 is disabled!
Use Formula.sha256 instead.
/Users/tbatters/homebrew/Library/Taps/keckcaves/homebrew-keckcaves/vrui-examples.rb:6:in <class:VruiExamplesBlueMarbleTex>' Please report this to the keckcaves/keckcaves tap! Warning: Calling 'depends_on :libpng' is deprecated! Use 'depends_on "libpng"' instead. /Users/tbatters/homebrew/Library/Taps/keckcaves/homebrew-keckcaves/vrui.rb:12:in class:Vrui'
Please report this to the keckcaves/keckcaves tap!

Error: Cannot tap keckcaves/keckcaves: invalid syntax in tap!