fix: return env names with error

pkg/tanka/errors.go

@@ -1,6 +1,9 @@
 package tanka
 
-import "fmt"
+import (
+	"fmt"
+	"strings"
+)
 
 // ErrNoEnv means that the given jsonnet has no Environment object
 // This must not be fatal, some operations work without
@@ -14,9 +17,10 @@ func (e ErrNoEnv) Error() string {
 
 // ErrMultipleEnvs means that the given jsonnet has multiple Environment objects
 type ErrMultipleEnvs struct {
-	path string
+	path  string
+	names []string
 }
 
 func (e ErrMultipleEnvs) Error() string {
-	return fmt.Sprintf("found multiple Environments in '%s'", e.path)
+	return fmt.Sprintf("found multiple Environments (%s) in '%s'", strings.Join(e.names, ", "), e.path)
 }

pkg/tanka/parse.go

@@ -198,7 +198,11 @@ func parseEnv(path string, opts jsonnet.Opts, evalFn evaluateFunc) (interface{},
 	var env *v1alpha1.Environment
 
 	if len(extractedEnvs) > 1 {
-		return data, nil, ErrMultipleEnvs{path}
+		names := make([]string, 0)
+		for _, exEnv := range extractedEnvs {
+			names = append(names, exEnv.Metadata().Name())
+		}
+		return data, nil, ErrMultipleEnvs{path, names}
 	} else if len(extractedEnvs) == 1 {
 		marshalled, err := json.Marshal(extractedEnvs[0])
 		if err != nil {