Print panic object when using ShouldNot(Panic())

matchers/panic_matcher.go

diff --git a/matchers/panic_matcher.go b/matchers/panic_matcher.go
index 75ab251..1e5d4d8 100644
--- a/matchers/panic_matcher.go
+++ b/matchers/panic_matcher.go
@@ -2,11 +2,14 @@
 
 import (
 	"fmt"
-	"github.com/onsi/gomega/format"
 	"reflect"
+
+	"github.com/onsi/gomega/format"
 )
 
-type PanicMatcher struct{}
+type PanicMatcher struct {
+	object interface{}
+}
 
 func (matcher *PanicMatcher) Match(actual interface{}) (success bool, err error) {
 	if actual == nil {
@@ -24,6 +27,7 @@
 	success = false
 	defer func() {
 		if e := recover(); e != nil {
+			matcher.object = e
 			success = true
 		}
 	}()
@@ -38,5 +42,5 @@
 }
 
 func (matcher *PanicMatcher) NegatedFailureMessage(actual interface{}) (message string) {
-	return format.Message(actual, "not to panic")
+	return format.Message(actual, fmt.Sprintf("not to panic, but panicked with <%T>: %v", matcher.object, matcher.object))
 }

matchers/panic_matcher_test.go

diff --git a/matchers/panic_matcher_test.go b/matchers/panic_matcher_test.go
index 17f3935..bb58a78 100644
--- a/matchers/panic_matcher_test.go
+++ b/matchers/panic_matcher_test.go
@@ -33,4 +33,13 @@
 			Ω(func() {}).ShouldNot(Panic())
 		})
 	})
+
+	Context("when assertion fails", func() {
+		It("should print the object passed to Panic", func() {
+			failuresMessages := InterceptGomegaFailures(func() {
+				Ω(func() { panic("ack!") }).ShouldNot(Panic())
+			})
+			Ω(failuresMessages).Should(ConsistOf(ContainSubstring("not to panic, but panicked with <string>: ack!")))
+		})
+	})
 })