diff --git a/Library/Contributions/manpages/brew.1.md b/Library/Contributions/manpages/brew.1.md
index 38b8644098..533fbfa01e 100644
--- a/Library/Contributions/manpages/brew.1.md
+++ b/Library/Contributions/manpages/brew.1.md
@@ -179,8 +179,7 @@ Note that these flags should only appear after a command.
     several different ways. See [SPECIFYING FORMULAE][].
 
     If `--debug` is passed and brewing fails, open an interactive debugging
-    session with access to IRB, ruby-debug, or a shell inside the temporary
-    build directory.
+    session with access to IRB or a shell inside the temporary build directory.
 
     If `--env=std` is passed, use the standard build environment instead of superenv.
 
@@ -332,14 +331,17 @@ Note that these flags should only appear after a command.
     Ensures all tapped formula are symlinked into Library/Formula and prunes dead
     formula from Library/Formula.
 
-  * `test` [--devel|--HEAD] <formula>:
+  * `test` [--devel|--HEAD] [--debug] <formula>:
     A few formulae provide a test method. `brew test <formula>` runs this
     test method. There is no standard output or return code, but it should
     generally indicate to the user if something is wrong with the installed
     formula.
 
-    To test the development or head version of a formula, `--devel` or
-    `--HEAD` must be passed.,
+    To test the development or head version of a formula, use `--devel` or
+    `--HEAD`.
+
+    If `--debug` is passed and the test fails, an interactive debugger will be
+    launched with access to IRB or a shell inside the temporary test directory.
 
     Example: `brew install jruby && brew test jruby`
 
diff --git a/Library/Homebrew/cmd/test.rb b/Library/Homebrew/cmd/test.rb
index b47a85ed47..6304507440 100644
--- a/Library/Homebrew/cmd/test.rb
+++ b/Library/Homebrew/cmd/test.rb
@@ -1,5 +1,6 @@
 require "extend/ENV"
 require "timeout"
+require "debrew"
 
 module Homebrew
   TEST_TIMEOUT_SECONDS = 5*60
@@ -50,11 +51,12 @@ module Homebrew
 
       f.extend(Test::Unit::Assertions)
       f.extend(Homebrew::Assertions)
+      f.extend(Debrew::Formula) if ARGV.debug?
 
       begin
         # tests can also return false to indicate failure
         Timeout::timeout TEST_TIMEOUT_SECONDS do
-          raise if f.test == false
+          raise if f.run_test == false
         end
       rescue FailedAssertion => e
         ofail "#{f.name}: failed"
diff --git a/Library/Homebrew/debrew.rb b/Library/Homebrew/debrew.rb
index fbddadbd53..f3d3dffa3d 100644
--- a/Library/Homebrew/debrew.rb
+++ b/Library/Homebrew/debrew.rb
@@ -21,6 +21,10 @@ module Debrew
     def install
       Debrew.debrew { super }
     end
+
+    def test
+      Debrew.debrew { super }
+    end
   end
 
   module Resource
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 23087ada61..261d3c5a0d 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -473,21 +473,23 @@ class Formula
     active_spec.verify_download_integrity(fn)
   end
 
-  def test
+  def run_test
     self.build = Tab.for_formula(self)
-    ret = nil
     mktemp do
       @testpath = Pathname.pwd
-      ret = instance_eval(&self.class.test)
-      @testpath = nil
+      test
     end
-    ret
+  ensure
+    @testpath = nil
   end
 
   def test_defined?
     false
   end
 
+  def test
+  end
+
   protected
 
   # Pretty titles the command and buffers stdout/stderr
@@ -769,9 +771,8 @@ class Formula
     end
 
     def test &block
-      return @test unless block_given?
       define_method(:test_defined?) { true }
-      @test = block
+      define_method(:test, &block)
     end
   end
 end
diff --git a/share/man/man1/brew.1 b/share/man/man1/brew.1
index e13b970132..d432311f7e 100644
--- a/share/man/man1/brew.1
+++ b/share/man/man1/brew.1
@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "BREW" "1" "July 2014" "Homebrew" "brew"
+.TH "BREW" "1" "September 2014" "Homebrew" "brew"
 .
 .SH "NAME"
 \fBbrew\fR \- The missing package manager for OS X
@@ -197,7 +197,7 @@ Install \fIformula\fR\.
 \fIformula\fR is usually the name of the formula to install, but it can be specified several different ways\. See \fISPECIFYING FORMULAE\fR\.
 .
 .IP
-If \fB\-\-debug\fR is passed and brewing fails, open an interactive debugging session with access to IRB, ruby\-debug, or a shell inside the temporary build directory\.
+If \fB\-\-debug\fR is passed and brewing fails, open an interactive debugging session with access to IRB or a shell inside the temporary build directory\.
 .
 .IP
 If \fB\-\-env=std\fR is passed, use the standard build environment instead of superenv\.
@@ -353,11 +353,14 @@ Tap a new formula repository from GitHub, or list existing taps\.
 Ensures all tapped formula are symlinked into Library/Formula and prunes dead formula from Library/Formula\.
 .
 .TP
-\fBtest\fR [\-\-devel|\-\-HEAD] \fIformula\fR
+\fBtest\fR [\-\-devel|\-\-HEAD] [\-\-debug] \fIformula\fR
 A few formulae provide a test method\. \fBbrew test <formula>\fR runs this test method\. There is no standard output or return code, but it should generally indicate to the user if something is wrong with the installed formula\.
 .
 .IP
-To test the development or head version of a formula, \fB\-\-devel\fR or \fB\-\-HEAD\fR must be passed\.,
+To test the development or head version of a formula, use \fB\-\-devel\fR or \fB\-\-HEAD\fR\.
+.
+.IP
+If \fB\-\-debug\fR is passed and the test fails, an interactive debugger will be launched with access to IRB or a shell inside the temporary test directory\.
 .
 .IP
 Example: \fBbrew install jruby && brew test jruby\fR