Pebble-SDK fails to upgrade/reinstall on High Sierra (no bottle)

[X] are reporting a bug others will be able to reproduce and not asking a question. If you're not sure or want to ask a question do so on our Discourse: https://discourse.brew.sh
[X] ran brew update and can still reproduce the problem?
[X] ran brew doctor, fixed all issues and can still reproduce the problem?
[X] ran brew gist-logs <formula> (where <formula> is the name of the formula that failed) and included the output link?

https://gist.github.com/a4171c8ee2ef6987dec4312d57d2384c

[X] if brew gist-logs didn't work: ran brew config and brew doctor and included their output with your issue?

To help us debug your issue please explain:

What you were trying to do (and why)

Pebble-SDK is out of date, trying to brew upgrade pebble-sdk

What happened (include command output)

no bottle was found:

 bottle do
    root_url "http://pebble-sdk-homebrew.s3.amazonaws.com"
    cellar :any
    sha256 "bcbebcf5c8f6631374044d86d3c6b007a9e6440c83c2fbb3741693e17818aa62" => :el_capitan
    sha256 "f14ce854035de57dbcc9f8ab390071491aee81a37456cf325b28ac5a80020989" => :sierra
  end

brew reinstall pebble-sdk
==> Reinstalling pebble/pebble-sdk/pebble-sdk 
==> Downloading http://pebble-sdk-homebrew.s3.amazonaws.com/pebble-sdk-4.5.el_ca
######################################################################## 100.0%
==> Pouring pebble-sdk-4.5.el_capitan.bottle.tar.gz
Error: undefined method `undent' for #<String:0x00007fec159c56e0>
Please report this bug:
  https://docs.brew.sh/Troubleshooting
/usr/local/Homebrew/Library/Taps/pebble/homebrew-pebble-sdk/pebble-sdk.rb:228:in `caveats'
/usr/local/Homebrew/Library/Homebrew/caveats.rb:17:in `caveats'
/System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/lib/ruby/2.3.0/forwardable.rb:202:in `empty?'
/usr/local/Homebrew/Library/Homebrew/formula_installer.rb:613:in `caveats'
/usr/local/Homebrew/Library/Homebrew/formula_installer.rb:664:in `finish'
/usr/local/Homebrew/Library/Homebrew/reinstall.rb:34:in `reinstall_formula'
/usr/local/Homebrew/Library/Homebrew/cmd/reinstall.rb:51:in `block in reinstall'
/usr/local/Homebrew/Library/Homebrew/cmd/reinstall.rb:45:in `each'
/usr/local/Homebrew/Library/Homebrew/cmd/reinstall.rb:45:in `reinstall'
/usr/local/Homebrew/Library/Homebrew/brew.rb:89:in `<main>'

What you expected to happen

An upgrade to pebble-sdk

Step-by-step reproduction instructions (by running brew install commands)

brew upgrade --force pebble-sdk or brew reinstall pebble-sdk

The bottle fails and it tries to install from source

There are no bottles for High Sierra or Mojave I am on high sierra. The bottle fails and it tries to install from source https://gist.github.com/a4171c8ee2ef6987dec4312d57d2384c

brew config
HOMEBREW_VERSION: 1.8.4-9-g30c90dc
ORIGIN: https://github.com/Homebrew/brew.git
HEAD: 30c90dcc3b03f9046b43af5efe256eda7263158c
Last commit: 17 hours ago
Core tap ORIGIN: https://github.com/Homebrew/homebrew-core
Core tap HEAD: 4fbee5d45821506f3b91045ca1dc8ed2e4f910aa
Core tap last commit: 30 minutes ago
HOMEBREW_PREFIX: /usr/local
HOMEBREW_DEV_CMD_RUN: 1
HOMEBREW_GITHUB_API_TOKEN: set
CPU: quad-core 64-bit haswell
Homebrew Ruby: 2.3.7 => /System/Library/Frameworks/Ruby.framework/Versions/2.3/usr/bin/ruby
Clang: 10.0 build 1000
Git: 2.19.2 => /usr/local/bin/git
Curl: 7.54.0 => /usr/bin/curl
Java: 1.8.0_102
macOS: 10.13.6-x86_64
CLT: 10.1.0.0.1.1539992718
Xcode: N/A
XQuartz: 2.7.11 => /opt/X11

Related Formulae missing High Sierra bottles: Homebrew/homebrew-core#18493

pebble / homebrew-pebble-sdk

Pebble-SDK fails to upgrade/reinstall on High Sierra (no bottle) #51