Add HOMEBREW_NO_GITHUB_API env var.

This patch allows users to "opt out" of using the GitHub API altogether
by setting the HOMEBREW_NO_GITHUB_API environment variable. The
value of the environment variable does not matter (it can even be
empty!).

For Bash/ZSH: export HOMEBREW_NO_GITHUB_API=1

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

3 files changed, 11 insertions, 1 deletions

diff --git a/Library/Contributions/manpages/brew.1.md b/Library/Contributions/manpages/brew.1.md
index 5524c070b..595c062a2 100644
--- a/Library/Contributions/manpages/brew.1.md
+++ b/Library/Contributions/manpages/brew.1.md
@@ -524,6 +524,10 @@ can take several different forms:
 
     *Note:* Homebrew will only try to print emoji on Lion or newer.
 
+  * HOMEBREW\_NO\_GITHUB\_API:
+    If set, Homebrew will not use the GitHub API for e.g searches or
+    fetching relevant issues on a failed install.
+
   * HOMEBREW\_SOURCEFORGE\_MIRROR:
     If set, Homebrew will use the value of `HOMEBREW_SOURCEFORGE_MIRROR` to
     select a SourceForge mirror for downloading bottles.
diff --git a/Library/Homebrew/cmd/search.rb b/Library/Homebrew/cmd/search.rb
index b2febbdba..7319b1d90 100644
--- a/Library/Homebrew/cmd/search.rb
+++ b/Library/Homebrew/cmd/search.rb
@@ -61,7 +61,7 @@ module Homebrew extend self
       count = local_results.length + tap_results.length
 
       if count == 0 and not blacklisted? query
-        puts "No formula found for #{query.inspect}. Searching open pull requests..."
+        puts "No formula found for #{query.inspect}."
         begin
           GitHub.find_pull_requests(rx) { |pull| puts pull }
         rescue GitHub::Error => e
diff --git a/Library/Homebrew/utils.rb b/Library/Homebrew/utils.rb
index f3ac5e447..97dd708af 100644
--- a/Library/Homebrew/utils.rb
+++ b/Library/Homebrew/utils.rb
@@ -254,6 +254,9 @@ module GitHub extend self
   Error = Class.new(StandardError)
 
   def open url, headers={}, &block
+    # This is a no-op if the user is opting out of using the GitHub API.
+    return if ENV['HOMEBREW_NO_GITHUB_API']
+
     require 'net/https' # for exception classes below
 
     default_headers = {'User-Agent' => HOMEBREW_USER_AGENT}
@@ -296,6 +299,9 @@ module GitHub extend self
   end
 
   def find_pull_requests rx
+    return if ENV['HOMEBREW_NO_GITHUB_API']
+    puts "Searching open pull requests..."
+
     query = rx.source.delete('.*').gsub('\\', '')
 
     each_issue_matching(query) do |issue|