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Using options results in descriptor pool error in generated code at import time. #150
Description
Summary
Using options results in descriptor pool error in generated code at import time.
Reproduction Steps
I'm trying out betterproto2, and running to an exception in the generated code when trying to add options to some of my files. Here's a minimal example:
# in example.proto
syntax = "proto3";
package betterproto.repro;
import "google/protobuf/descriptor.proto";
message ExampleOptions {
string foo = 1 [targets = TARGET_TYPE_MESSAGE];
}
extend google.protobuf.MessageOptions {
optional ExampleOptions example_options = 50000;
}
message MyMessage {
option (example_options).foo = "bar";
string baz = 1;
}compiled with
uv run python -m grpc_tools.protoc --python_betterproto2_out generated/ --python_betterproto2_opt=google_protobuf_descriptors -I. example.protoand then try to import the generated code with
uv run python -c "from generated.betterproto.repro import MyMessage"
Expected Results
An exception is raised
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/[snip]/generated/betterproto/repro/__init__.py", line 52, in <module>
EXAMPLE_PROTO_DESCRIPTOR = default_google_proto_descriptor_pool.AddSerializedFile(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: Couldn't build proto file into descriptor pool: Depends on file 'google/protobuf/descriptor.proto', but it has not been loaded
Actual Results
The generated code should import without errors.
Potential fix/workaround: If I add
from ...google import protobuf as ___google__protobuf__in the generated file (near the top), that resolves the error.
System Information
I'm using uv instead of pip. I'm fairly certain that's not the issue.
$ uv run python -m grpc_tools.protoc --version
libprotoc 31.1
$ uv run python --version
Python 3.12.11
$ uv pip show betterproto2
Name: betterproto2
Version: 0.9.0
Location: [snip]/.venv/lib/python3.12/site-packages
Requires: python-dateutil, typing-extensions
Required-by: betterproto2-compiler
$ uv pip show betterproto2_compiler
Name: betterproto2-compiler
Version: 0.9.0
Location: [snip]/.venv/lib/python3.12/site-packages
Requires: betterproto2, jinja2, ruff, typing-extensions
Required-by:
Checklist
- I have searched the issues for duplicates.
- I have shown the entire traceback, if possible.
- I have verified this issue occurs on the latest prelease of betterproto which can be installed using
pip install -U --pre betterproto, if possible.
Activity
drewfustin commentedon Sep 9, 2026
Proposed fix in #255.
Generated modules now import each foreign dependency package (including
google.protobuffor custom options) and register same-package files in dependency order beforeAddSerializedFile. That matches the import workaround in the issue report.