explain why gomega refuses to compare <nil> to <nil>

matchers/assignable_to_type_of_matcher.go

diff --git a/matchers/assignable_to_type_of_matcher.go b/matchers/assignable_to_type_of_matcher.go
index 7f8897b..89a1fc2 100644
--- a/matchers/assignable_to_type_of_matcher.go
+++ b/matchers/assignable_to_type_of_matcher.go
@@ -2,8 +2,9 @@
 
 import (
 	"fmt"
-	"github.com/onsi/gomega/format"
 	"reflect"
+
+	"github.com/onsi/gomega/format"
 )
 
 type AssignableToTypeOfMatcher struct {
@@ -12,7 +13,7 @@
 
 func (matcher *AssignableToTypeOfMatcher) Match(actual interface{}) (success bool, err error) {
 	if actual == nil || matcher.Expected == nil {
-		return false, fmt.Errorf("Refusing to compare <nil> to <nil>.")
+		return false, fmt.Errorf("Refusing to compare <nil> to <nil>.\nBe explicit and use BeNil() instead.  This is to avoid mistakes where both sides of an assertion are erroneously uninitialized.")
 	}
 
 	actualType := reflect.TypeOf(actual)

matchers/equal_matcher.go

diff --git a/matchers/equal_matcher.go b/matchers/equal_matcher.go
index 9f8f80a..d186597 100644
--- a/matchers/equal_matcher.go
+++ b/matchers/equal_matcher.go
@@ -2,8 +2,9 @@
 
 import (
 	"fmt"
-	"github.com/onsi/gomega/format"
 	"reflect"
+
+	"github.com/onsi/gomega/format"
 )
 
 type EqualMatcher struct {
@@ -12,7 +13,7 @@
 
 func (matcher *EqualMatcher) Match(actual interface{}) (success bool, err error) {
 	if actual == nil && matcher.Expected == nil {
-		return false, fmt.Errorf("Refusing to compare <nil> to <nil>.")
+		return false, fmt.Errorf("Refusing to compare <nil> to <nil>.\nBe explicit and use BeNil() instead.  This is to avoid mistakes where both sides of an assertion are erroneously uninitialized.")
 	}
 	return reflect.DeepEqual(actual, matcher.Expected), nil
 }