fix: update ReferrerNotFound error to be more accurate

errors/pluginerrors.go

@@ -106,10 +106,10 @@ var (
 	})
 
 	// ErrorCodeReferrersNotFound is returned if there is no ReferrerStore set.
-	ErrorCodeReferrersNotFound = Register("errcode", ErrorDescriptor{
-		Value:       "REFERRERS_NOT_FOUND",
-		Message:     "referrers not found",
-		Description: "No referrers are found. Please verify the subject has attached expected artifacts and refer to https://ratify.dev/docs/reference/store/ to investigate Referrer Store configuration.",
+	ErrorCodeEmptyVerifierReport = Register("errcode", ErrorDescriptor{
+		Value:       "EMPTY_VERIFIER_REPORT",
+		Message:     "empty verifier report",
+		Description: "No verifier report was generated. This might be due to various factors, such as a misconfiguration in the Referrer Store preventing access to the registry, lack of artifacts attached to the image, or the absence of appropriate verifiers corresponding to the referenced image artifacts.",
 	})
 
 	// Generic errors happen in plugins

errors/types.go

@@ -68,6 +68,7 @@ type Error struct {
 	PluginName    string        `json:"pluginName,omitempty"`
 	LinkToDoc     string        `json:"linkToDoc,omitempty"`
 	Stack         string        `json:"stack,omitempty"`
+	Description   string        `json:"description,omitempty"`
 }
 
 // ErrorDescriptor provides relevant information about a given error code.
@@ -124,6 +125,11 @@ func (ec ErrorCode) Message() string {
 	return ec.Descriptor().Message
 }
 
+// Description returned the description of this error code.
+func (ec ErrorCode) Description() string {
+	return ec.Descriptor().Description
+}
+
 // String returns the canonical identifier for this error code.
 func (ec ErrorCode) String() string {
 	return ec.Descriptor().Value
@@ -149,6 +155,10 @@ func (ec ErrorCode) WithLinkToDoc(link string) Error {
 	return newError(ec, ec.Message()).WithLinkToDoc(link)
 }
 
+func (ec ErrorCode) WithDescription() Error {
+	return newError(ec, ec.Message()).WithDescription()
+}
+
 // WithPluginName returns a new Error object with pluginName set.
 func (ec ErrorCode) WithPluginName(pluginName string) Error {
 	return newError(ec, ec.Message()).WithPluginName(pluginName)
@@ -223,6 +233,10 @@ func (e Error) Error() string {
 		errStr += fmt.Sprintf(", Detail: %v", e.Detail)
 	}
 
+	if e.Description != "" {
+		errStr += fmt.Sprintf(", Description: %v", e.Description)
+	}
+
 	if e.Stack != "" {
 		errStr += fmt.Sprintf(", Stack trace: %s", e.Stack)
 	}
@@ -261,6 +275,11 @@ func (e Error) WithLinkToDoc(link string) Error {
 	return e
 }
 
+func (e Error) WithDescription() Error {
+	e.Description = e.Code.Description()
+	return e
+}
+
 // IsEmpty returns true if the error is empty.
 func (e Error) IsEmpty() bool {
 	return e == emptyError

pkg/executor/core/executor.go

@@ -83,7 +83,7 @@ func (executor Executor) verifySubjectInternal(ctx context.Context, verifyParame
 	}
 	if executor.PolicyEnforcer.GetPolicyType(ctx) == pt.ConfigPolicy {
 		if len(verifierReports) == 0 {
-			return types.VerifyResult{}, errors.ErrorCodeReferrersNotFound.WithComponentType(errors.Executor)
+			return types.VerifyResult{}, errors.ErrorCodeEmptyVerifierReport.WithComponentType(errors.Executor).WithDescription()
 		}
 	}
 	// If it requires embedded Rego Policy Engine make the decision, execute