From 9aecb1be2b89843c66852ad11ba6c22ef10d2e64 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Mon, 21 Sep 2015 15:10:23 +0100
Subject: [PATCH] formula: increase fail log lines, allow config.

The default is almost never useful. 15 seems like a good medium as it'll
not fill a 80x24 default but provides a bit more context. Also allow it
to be overriden for developers and `test-bot`.
---
 Library/Homebrew/formula.rb | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 36eb41b5ac..3e7e24d431 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1304,8 +1304,14 @@ class Formula
       $stdout.flush
 
       unless $?.success?
+        log_lines = ENV["HOMEBREW_FAIL_LOG_LINES"]
+        log_lines ||= "15"
+
         log.flush
-        Kernel.system "/usr/bin/tail", "-n", "5", logfn unless verbose
+        unless verbose
+          puts "Last #{log_lines} lines from #{logfn}:"
+          Kernel.system "/usr/bin/tail", "-n", log_lines, logfn
+        end
         log.puts
 
         require "cmd/config"