github: produce better curl error messages. (#441)

* global: add RUBY_TWO global variable.

* test-bot: use RUBY_TWO global variable.

* github: produce better curl error messages.

If we don't know why curl has failed then ensure that the error messages
that it produced are included as part of the user output.

4 files changed, 21 insertions, 11 deletions

diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index b09d2608a..40e99f7b6 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -647,11 +647,9 @@ module Homebrew
       @category = __method__
       return if @skip_homebrew
 
-      ruby_two = RUBY_VERSION.split(".").first.to_i >= 2
-
       if @tap.nil?
         tests_args = []
-        if ruby_two
+        if RUBY_TWO
           tests_args << "--official-cmd-taps"
           tests_args << "--coverage" if ENV["TRAVIS"]
         end
@@ -892,7 +890,7 @@ module Homebrew
 
     ENV["HOMEBREW_DEVELOPER"] = "1"
     ENV["HOMEBREW_SANDBOX"] = "1"
-    ENV["HOMEBREW_RUBY_MACHO"] = "1" if RUBY_VERSION.split(".").first.to_i >= 2
+    ENV["HOMEBREW_RUBY_MACHO"] = "1" if RUBY_TWO
     ENV["HOMEBREW_NO_EMOJI"] = "1"
     ENV["HOMEBREW_FAIL_LOG_LINES"] = "150"
     ENV["HOMEBREW_EXPERIMENTAL_FILTER_FLAGS_ON_DEPS"] = "1"
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index 25f2d42f0..9554dd536 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -30,6 +30,7 @@ else
   )
 end
 RUBY_BIN = RUBY_PATH.dirname
+RUBY_TWO = RUBY_VERSION.split(".").first.to_i >= 2
 
 HOMEBREW_USER_AGENT_CURL = ENV["HOMEBREW_USER_AGENT_CURL"]
 HOMEBREW_USER_AGENT_RUBY = "#{ENV["HOMEBREW_USER_AGENT"]} ruby/#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL}"
diff --git a/Library/Homebrew/utils/curl.rb b/Library/Homebrew/utils/curl.rb
index a1653d46c..db3534542 100644
--- a/Library/Homebrew/utils/curl.rb
+++ b/Library/Homebrew/utils/curl.rb
@@ -1,4 +1,5 @@
 require "pathname"
+require "open3"
 
 def curl_args(extra_args=[])
   curl = Pathname.new ENV["HOMEBREW_CURL"]
@@ -19,6 +20,15 @@ def curl(*args)
 end
 
 def curl_output(*args)
-  curl_args = curl_args(args) - ["--fail"]
-  Utils.popen_read_text(*curl_args)
+  curl_args = curl_args(args)
+  curl_args -= ["--fail"]
+  if RUBY_TWO
+    curl_args -= ["--silent"]
+    Open3.popen3(*curl_args) do |_, stdout, stderr, wait_thread|
+      [stdout.read, stderr.read, wait_thread.value]
+    end
+  else
+    output = Utils.popen_read_text(*curl_args)
+    [output, nil, $?]
+  end
 end
diff --git a/Library/Homebrew/utils/github.rb b/Library/Homebrew/utils/github.rb
index 36f6257f7..c5dbedd6c 100644
--- a/Library/Homebrew/utils/github.rb
+++ b/Library/Homebrew/utils/github.rb
@@ -146,7 +146,8 @@ module GitHub
 
       args += ["--dump-header", "#{headers_tmpfile.path}"]
 
-      output, _, http_code = curl_output(url.to_s, *args).rpartition("\n")
+      output, errors, status = curl_output(url.to_s, *args)
+      output, _, http_code = output.rpartition("\n")
       output, _, http_code = output.rpartition("\n") if http_code == "000"
       headers = headers_tmpfile.read
     ensure
@@ -159,8 +160,8 @@ module GitHub
     end
 
     begin
-      if !http_code.start_with?("2") && !$?.success?
-        raise_api_error(output, http_code, headers)
+      if !http_code.start_with?("2") && !status.success?
+        raise_api_error(output, errors, http_code, headers)
       end
       json = Utils::JSON.load output
       if block_given?
@@ -173,7 +174,7 @@ module GitHub
     end
   end
 
-  def raise_api_error(output, http_code, headers)
+  def raise_api_error(output, errors, http_code, headers)
     meta = {}
     headers.lines.each do |l|
       key, _, value = l.delete(":").partition(" ")
@@ -197,7 +198,7 @@ module GitHub
       raise HTTPNotFoundError, output
     else
       error = Utils::JSON.load(output)["message"] rescue nil
-      error ||= output
+      error ||= "curl failed! #{errors}"
       raise Error, error
     end
   end