Elaborate error message

Author: dcharkes

pkgs/code_assets/lib/src/code_assets/validation.dart

@@ -301,7 +301,10 @@ ValidationErrors _validateFile(
 }) {
   final errors = <String>[];
   if (mustBeAbsolute && !uri.isAbsolute) {
-    errors.add('$name (${uri.toFilePath()}) must be an absolute path.');
+    errors.add(
+      '$name (${uri.toFilePath()}) must be an absolute path. '
+      'Prefer constructing it via `input.outputDirectoryShared`.',
+    );
   }
   if (mustExist && !File.fromUri(uri).existsSync()) {
     errors.add('$name (${uri.toFilePath()}) does not exist as a file.');

pkgs/data_assets/lib/src/data_assets/validation.dart

@@ -129,7 +129,11 @@ ValidationErrors _validateFile(
 }) {
   final errors = <String>[];
   if (mustBeAbsolute && !uri.isAbsolute) {
-    errors.add('$name (${uri.toFilePath()}) must be an absolute path.');
+    errors.add(
+      '$name (${uri.toFilePath()}) must be an absolute path. '
+      'Prefer constructing it via `input.outputDirectoryShared` or '
+      '`input.packageRoot`.',
+    );
   }
   if (mustExist && !File.fromUri(uri).existsSync()) {
     errors.add('$name (${uri.toFilePath()}) does not exist as a file.');