[URGENT] Dynamic build not showing custom method options in .Options map

[azykophus]

Title: Dynamic build not showing custom method options in .Options map

Description:

Hello, I’m running into a problem where custom method options (extensions on google.protobuf.MethodOptions) are not appearing in the .Options map in my template, even though I’ve built protoc-gen-doc with -tags dynamic.

Steps to Reproduce

1. Minimal .proto Files

   • test_extension.proto:

     syntax = "proto3";
     
     package test.extensions;
     
     import "google/protobuf/descriptor.proto";
     
     enum MyErrorCode {
       UNKNOWN = 0;
       BAD_REQUEST = 1;
     }
     
     extend google.protobuf.MethodOptions {
       string path = 50001;
       repeated MyErrorCode error_codes = 50002;
     }

   • test_service.proto:

     syntax = "proto3";
     
     package test.service;
     
     import "test_extension.proto";
     
     service MyService {
       rpc Foo (FooReq) returns (FooResp) {
         option (test.extensions.path) = "/foo";
         option (test.extensions.error_codes) = BAD_REQUEST;
         option (test.extensions.error_codes) = UNKNOWN;
       }
     }
     
     message FooReq {}
     message FooResp {}

2. Template (test_template.tmpl):

   {{ range .Files -}}
   ## File: {{ .Name }}
   
   {{ range .Services -}}
   ### Service: {{ .Name }}
   
   {{ range .Methods -}}
   - **Method**: {{ .Name }}
   - **Options**:
   {{ range $k, $v := .Options }}
     - `{{ $k }}` = `{{ $v }}`
   {{ end }}
   
   {{ end -}}
   {{ end -}}
   {{ end -}} 
   

3. Build protoc-gen-doc with dynamic tag:

   cd protoc-gen-doc
   git checkout v1.5.1  # or tried main as well
   go build -tags dynamic -o protoc-gen-doc-dynamic ./cmd/protoc-gen-doc
   # Verified ./protoc-gen-doc-dynamic --version => 1.5.1
   

4. Run protoc:

  --plugin=protoc-gen-doc=./protoc-gen-doc-dynamic \
  -I=. \
  --include_imports \
  --doc_out=. \
  --doc_opt=test_template.tmpl,output.md \
  test_extension.proto \
  test_service.proto

Expected Behaviour

The generated output.md should list the custom method options under - **Options**:.

For example:

### Service: MyService

- **Method**: Foo
- **Options**:
  - `(test.extensions.path)` = `/foo`
  - `(test.extensions.error_codes)` = `BAD_REQUEST`
  - `(test.extensions.error_codes)` = `UNKNOWN`

Actual Behaviour

The output is:

For example:

## File: test_service.proto
### Service: MyService

- **Method**: Foo
- **Options**:

Additional Evidence

Decoded descriptor (protoc --decode_raw) does show 50001: "/foo" and 50002: "\001\000", indicating the custom fields are present in the compiled descriptor.
I’ve tried --include_imports, multiple versions of protoc-gen-doc, and ensuring the correct plugin is used (verified by absolute path).
The same result occurs with v1.5.1 and with main (when built with -tags dynamic).

Question / Request

Is this a known limitation or bug that method-level custom options are not populated into .Options even under the dynamic build?
Or is there a known workaround for reading these extension fields on RPC methods?