Problem matchers: Don't require relative paths to start with ./ or ../

__tests__/setup-go.test.ts

@@ -497,6 +497,16 @@ describe('setup-go', () => {
     expect(annotation.message).toBe('undefined: fmt.Printl');
   });
 
+  it('matches on unix path down the tree', async () => {
+    let line = 'foo/main.go:13:2: undefined: fmt.Printl';
+    let annotation = testMatch(line);
+    expect(annotation).toBeDefined();
+    expect(annotation.line).toBe(13);
+    expect(annotation.column).toBe(2);
+    expect(annotation.file).toBe('foo/main.go');
+    expect(annotation.message).toBe('undefined: fmt.Printl');
+  });
+
   it('matches on rooted unix path', async () => {
     let line = '/assert.go:4:1: missing return at end of function';
     let annotation = testMatch(line);

matchers.json

@@ -4,7 +4,7 @@
             "owner": "go",
             "pattern": [
                 {
-                    "regexp": "^\\s*(\\.{0,2}[\\/\\\\].+\\.go):(?:(\\d+):(\\d+):)? (.*)",
+                    "regexp": "^\\s*(.+\\.go):(?:(\\d+):(\\d+):)? (.*)",
                     "file": 1,
                     "line": 2,
                     "column": 3,
@@ -13,4 +13,4 @@
             ]
         }
     ]
-}
+}