fixup! fix(material/schematics): gracefully skip broken css files

Author: mmalerba

src/material/schematics/ng-generate/mdc-migration/BUILD.bazel

@@ -91,6 +91,7 @@ jasmine_node_test(
         "//src/material/schematics:collection_assets",
         "//src/material/schematics:ng_generate_assets",
     ],
+    shard_count = 10,
     deps = [
         ":unit_tests_bundle",
         # Runtime dependencies needed by the test and actual migration sources. These need

src/material/schematics/ng-generate/mdc-migration/rules/theming-styles.ts

@@ -40,7 +40,8 @@ export class ThemingStylesMigration extends Migration<ComponentMigrator[], Schem
     try {
       return processor.process(styles, {syntax: scss}).toString();
     } catch (e) {
-      console.warn(`Failed to process stylesheet: `, filename);
+      console.error(e);
+      console.warn(`Failed to process stylesheet: ${filename} (see error above).`);
       return styles;
     }
   }

src/material/schematics/ng-update/migrations/legacy-components-v15/index.ts

@@ -40,7 +40,8 @@ export class LegacyComponentsMigration extends Migration<null> {
     try {
       processor.process(stylesheet.content, {syntax: scss}).sync();
     } catch (e) {
-      console.warn(`Failed to process stylesheet: `, stylesheet.filePath);
+      console.error(e);
+      console.warn(`Failed to process stylesheet: ${stylesheet.filePath} (see error above).`);
     }
   }