get_selection() fails if a single graphics primitive is selected

Summary

(I realize this is probably an IPC API issue and not a kicad-python one but since I'm only using the API via kicad-python, I'm just reporting it here. I'm certain it will reach the correct people regardless. :-) )

Considering the following snippet:

import kipy

kicad = kipy.KiCad()
board = kicad.get_board()
board.get_selection()

If I have no selection, I get an empty list. If I have selected multiple items, e.g. two single-segment lines, I get a list of two kipy.board_types.BoardShape objects. If I select a single line or a single arc, I get:

ApiError                                  Traceback (most recent call last)
Cell In[44], line 1
----> 1 board.get_selection()

File ~/src/hatlabs/forced-neckdown/.venv/lib/python3.13/site-packages/kipy/board.py:513, in Board.get_selection(self, types)
    508 else:
    509     cmd.types.extend(types or [])
    511 return [
    512     unwrap(item)
--> 513     for item in self._kicad.send(
    514         cmd, editor_commands_pb2.SelectionResponse
    515     ).items
    516 ]

File ~/src/hatlabs/forced-neckdown/.venv/lib/python3.13/site-packages/kipy/client.py:90, in KiCadClient.send(self, command, response_type)
     88     return response
     89 else:
---> 90     raise ApiError(f"KiCad returned error: {reply.status.error_message}",
     91                    raw_message=reply.status.error_message, code=reply.status.status)

ApiError: KiCad returned error: KiCad is busy and cannot respond to API requests right now

I'm also getting the same error for some single pad selections while others work.

Reproduction steps

1. Open PCB Editor.
2. Draw a couple of lines or arcs.
3. Select one of them.
4. Run the above code snippet e.g. in a Jupyter Notebook or in a standalone script.

Version Info

Please include all the requested information below. If you do not, your issue may be closed.

• Python version:
• kicad-python version: 7b8a97f7 (current main HEAD)

KiCad full version info: Insert the output of kicad-cli version --format about, or the full KiCad version text found in the KiCad About dialog, between the sets of triple backticks below

Application: KiCad PCB Editor arm64 on arm64

Version: 9.0.0-rc2-161-gd90862b444, release build

Libraries:
	wxWidgets 3.2.6
	FreeType 2.13.3
	HarfBuzz 10.2.0
	FontConfig 2.15.0
	libcurl/8.7.1 (SecureTransport) LibreSSL/3.3.6 zlib/1.2.12 nghttp2/1.63.0

Platform: macOS Sequoia Version 15.2 (Build 24C101), 64 bit, Little endian, wxMac
OpenGL: Apple, Apple M1 Max, 2.1 Metal - 89.3

Build Info:
	Date: Jan 28 2025 02:22:17
	wxWidgets: 3.2.6 (wchar_t,wx containers)
	Boost: 1.87.0
	OCC: 7.8.1
	Curl: 8.7.1
	ngspice: 44
	Compiler: Clang 16.0.0 with C++ ABI 1002
	KICAD_IPC_API=ON