warning: missing `package` declaration
 --> testdata/extend/decl_empty_pkg.proto
   = note: not explicitly specifying a package places the file in the unnamed
           package; using it strongly is discouraged

error: mismatched types
  --> testdata/extend/decl_empty_pkg.proto:44:5
   |
27 |             type: ".int32"
   |                   -------- expected due to this
...
43 |     optional .int32 x1 = 1;
44 |     optional int32 x2 = 2;
   |     ^^^^^^^^^^^^^^ expected `int32`, found `int32`
   |
   = note: expected: message type `int32`
              found: scalar type `int32`

error: mismatched types
  --> testdata/extend/decl_empty_pkg.proto:45:5
   |
32 |             type: "int32"
   |                   ------- expected due to this
...
44 |     optional int32 x2 = 2;
45 |     optional .int32 y1 = 3;
   |     ^^^^^^^^^^^^^^^ expected `int32`, found `int32`
   |
   = note: expected: scalar type `int32`
              found: message type `int32`

encountered 2 errors and 1 warning
