subagent transcript

session 17f09f89 · workflow wf_1ced79bb
← 17f09f89 · archive
delegated task
FreeCAD is ported to WebAssembly (JSPI + native-EH, static CPython 3.14, no dlopen, no subprocess, single-thread, Qt 6.11). 17 workbenches already wor
▸ Magik
FreeCAD is ported to WebAssembly (JSPI + native-EH, static CPython 3.14, no dlopen, no subprocess, single-thread, Qt 6.11). 17 workbenches already work incl. Part/PartDesign/Sketcher/Measure/Draft/Assembly/TechDraw/Mesh + numpy + PySide6 + pivy._coin. Source tree: /home/magik6k/lcad-wasm/freecad-port/FreeCAD (branch wasm-parity-push). Build tree (already configured, DO NOT build — read only): /opt/toolchains/src/freecad-gui-build. The module-enablement pipeline is documented in the memory files at /home/magik6k/.claude/projects/-home-magik6k-lcad-wasm/memory/ (read freecad-wasm-parity-roadmap.md and freecad-wasm-viewport.md FIRST — they describe the src/Main/CMakeLists.txt inittab generator, FREECAD_WASM_EXTRA_PY_MODULES / FREECAD_WASM_EXTRA_LINK_LIBS, SHARED->STATIC conversion, data-packaging with file_packager, and known gotchas). Constraints that shape feasibility: NO subprocess/fork/exec, NO dlopen (all C-ext modules static via inittab), NO threads (QThreadPool/QtConcurrent absent), NO listen sockets, wasm32 4GB ceiling. C++ deps must be new-EH (-fwasm-exceptions -sWASM_LEGACY_EXCEPTIONS=0). Pure-Python addons are fine; native ones need static linking. Your job: READ ONLY. Do not edit source, do not run cmake/ninja/emcc. Produce an actionable plan a build engineer can execute. Assess Plot workbench + matplotlib for wasm. numpy 2.4.6 already works (static, 12 C-exts). matplotlib needs a pure-Python-ish backend (Agg is C; the Qt backend needs PySide6 which works). Determine: can matplotlib be bundled (which C-extensions does it need — _path, _image, ft2font, _tri, kiwisolver, contourpy — and are they buildable static new-EH like numpy)? Or is there an Agg-free path? What does Plot/InitGui import? Give the realistic verdict + the C-extension build list (mirroring the numpy-wasm static build approach) + which files register them. Read src/Mod/Plot.
Fable
thinking
I'm looking into the Plot workbench in the FreeCAD codebase.
Fable
⚙ Bash {"command": "ls -la /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/", "description": "List Plot module directory"}
tool result
total 28
drwxr-xr-x 1 magik6k magik6k    76 Jul  3 17:58 .
drwxr-xr-x 1 magik6k magik6k   512 Jul  3 17:58 ..
-rw-r--r-- 1 magik6k magik6k   353 Jul  3 17:58 CMakeLists.txt
-rw-r--r-- 1 magik6k magik6k   118 Jul  3 17:58 plot.dox
-rw-r--r-- 1 magik6k magik6k 13561 Jul  3 17:58 Plot.py
-rw-r--r-- 1 magik6k magik6k   383 Jul  3 17:58 README.md
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
⚙ Bash {"command": "cat /home/magik6k/.claude/projects/-home-magik6k-lcad-wasm/memory/freecad-wasm-parity-roadmap.md", "description": "Read parity roadmap memory"}
tool result
---
name: freecad-wasm-parity-roadmap
description: "Evidence-based roadmap to full FreeCAD desktop parity in wasm — current ~35%, ~80% ceiling, pivy._coin is the linchpin, phase order, hard blockers"
metadata:
  node_type: memory
  type: project
  originSessionId: 17f09f89-ce7c-4f49-aa6a-cf0521026805
---

Roadmap researched 2026-07-05 (7-agent workflow over the actual FreeCAD source + wasm build + deploy). Rendered as an artifact for the user. Current desktop parity ≈ **35%** (usage-weighted; th  …[truncated]
Fable
thinking
I'm looking at the Plot module files now.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/Plot.py"}
tool result
1	# SPDX-License-Identifier: LGPL-2.1-or-later
2	
3	# ***************************************************************************
4	# *   Copyright (c) 2011, 2012 Jose Luis Cercos Pita <jlcercos@gmail.com>   *
5	# *                                                                         *
6	# *   This program is free software; you can redistribute it and/or modify  *
7	# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
8	# *   as published by the Free Software Foundati  …[truncated]
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/CMakeLists.txt"}
tool result
1	# SPDX-License-Identifier: LGPL-2.1-or-later
2	
3	SET(PlotMain_SRCS
4	    Plot.py
5	)
6	SOURCE_GROUP("" FILES ${PlotMain_SRCS})
7	
8	SET(all_files ${PlotMain_SRCS})
9	
10	ADD_CUSTOM_TARGET(Plot ALL
11	    SOURCES ${all_files}
12	)
13	
14	fc_copy_sources(Plot "${CMAKE_BINARY_DIR}/Mod/Plot" ${all_files})
15	
16	INSTALL(
17	    FILES
18	        ${PlotMain_SRCS}
19	    DESTINATION
20	        Mod/Plot
21	)
22
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/README.md"}
tool result
1	## Introduction
2	
3	Plot is a workbench that provides an interface to perform plots.
4	
5	From FreeCAD v0.20 Plot workbench is split into an [external addon](https://github.com/FreeCAD/freecad.plot)
6	
7	## Documentation
8	
9	Plot documentation can be found on the FreeCAD wiki [Plot Workbench](https://wiki.freecad.org/Plot_Workbench) page
10	
11	## Authors
12	
13	Jose Luis Cercós Pita <jlcercos@gmail.com>
14
Fable
thinking
I'm realizing Plot.py is just a legacy compatibility shim, and the actual workbench lives in an external addon now. The core question is really about matplotlib's feasibility, so let me look into the numpy-wasm build approach to understand the constraints better.
Fable
⚙ Bash {"command": "find /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot -type f; echo \"---InitGui search---\"; grep -rl \"InitGui\" /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot 2>/dev/null; echo \"---matplotlib anywhere in…
tool result
/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/CMakeLists.txt
/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/Plot.py
/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/README.md
/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod/Plot/plot.dox
---InitGui search---
---matplotlib anywhere in deploy/build---
/home/magik6k/lcad-wasm/freecad-port/FreeCAD/cMake/FindMatplotlib.cmake
/home/magik6k/lcad-wasm/freecad-port/FreeCAD/cMake/FreeCAD_Helpers/SetupMatplotlib.cmake
/h  …[truncated]
Fable
⚙ Bash {"command": "ls -la /home/magik6k/lcad-wasm/freecad-port/pyside-port/build/numpy-wasm/ 2>/dev/null; echo \"===\"; find /home/magik6k/lcad-wasm/freecad-port/pyside-port/build/numpy-wasm -maxdepth 2 -type f 2>/dev/null | head -50", "descripti…
tool result
===
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I need to correct my understanding of where the numpy-wasm build is located—it's in the lcad-wasm directory structure, not under freecad-port. Let me dig into that numpy build to see how the static C extension initialization table is set up.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/pyside-port/build/numpy-wasm 2>/dev/null; ls -la; echo \"=== scripts ===\"; find . -maxdepth 1 -name \"*.sh\" -o -maxdepth 1 -name \"*.py\" 2>/dev/null | head", "description": "List numpy-wasm build d…
tool result
total 32100
drwxr-xr-x 1 magik6k magik6k      642 Jul  6 02:09 .
drwxr-xr-x 1 magik6k magik6k      314 Jul  6 02:11 ..
-rw-r--r-- 1 magik6k magik6k        0 Jul  5 19:58 assemble.log
-rw-r--r-- 1 magik6k magik6k     1881 Jul  5 19:58 assemble.sh
drwxr-xr-x 1 magik6k magik6k      238 Jul  6 02:09 builddir
-rw-r--r-- 1 magik6k magik6k     4113 Jul  5 20:20 BUILD.sh
drwxr-xr-x 1 magik6k magik6k      116 Jul  5 19:45 crossenv
-rw-r--r-- 1 magik6k m  …[truncated]
Fable
⚙ Bash {"command": "cat /home/magik6k/.claude/projects/-home-magik6k-lcad-wasm/memory/freecad-wasm-viewport.md 2>/dev/null | sed -n '1,200p'", "description": "Read viewport memory for module pipeline"}
tool result
---
name: freecad-wasm-viewport
description: How the FreeCAD-wasm 3D viewport was made to render (offscreen FBO + QPainter blit) and the asyncify-safe way to create a 3D view
metadata: 
  node_type: memory
  type: project
  originSessionId: 18e25685-98b5-4959-935f-943b1af20789
---

FreeCAD WebAssembly port (/home/magik6k/lcad-wasm/freecad-port/FreeCAD, build dir /opt/toolchains/src/freecad-gui-build). The 3D viewport now RENDERS (gradient background, navigation cube, RGB axis cross all composite  …[truncated]
Fable
thinking
I need to examine the numpy BUILD.sh and make-archive.sh scripts to understand the static build pattern, then trace how it gets registered in the inittab and how the C extensions are wired up in the CMake configuration.
Fable
⚙ Bash {"command": "cat /home/magik6k/lcad-wasm/pyside-port/build/numpy-wasm/make-archive.sh; echo \"=========ASSEMBLE=========\"; cat /home/magik6k/lcad-wasm/pyside-port/build/numpy-wasm/assemble.sh", "description": "Read numpy archive/assemble s…
tool result
#!/usr/bin/env bash
# Assemble ONE self-contained fat archive libnumpy_wasm.a for static inittab linking.
source /home/magik6k/lcad-wasm/pyside-port/build/numpy-wasm/setup-env.sh
set -uo pipefail
BD=/home/magik6k/lcad-wasm/pyside-port/build/numpy-wasm/builddir
OUT=/home/magik6k/lcad-wasm/pyside-port/build/numpy-wasm
EMAR=/opt/toolchains/emsdk/upstream/emscripten/emar
EMNM=/opt/toolchains/emsdk/upstream/emscripten/emnm
cd "$BD"

# ---- module private objects (dedup'd) ----
# Full-include modules   …[truncated]
Fable
⚙ Bash {"command": "grep -n -i \"numpy\\|EXTRA_PY_MODULES\\|EXTRA_LINK_LIBS\\|inittab\\|pivy\\|_coin\" /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Main/CMakeLists.txt | head -80", "description": "Find numpy/inittab registration in Main CMakeL…
tool result
10:    # must be registered on the interpreter's inittab before Py_Initialize().
87:    function(freecad_wasm_generate_inittab outfile)
100:                string(APPEND _regs "    PyImport_AppendInittab(\"${_regname}\", PyInit_${_pymodx});\n")
120:            string(APPEND _regs "    PyImport_AppendInittab(\"${_pymod}\", PyInit_${_pymod});\n")
126:            "void freecadWasmRegisterInittab()\n"
134:    set(FREECAD_WASM_EXTRA_PY_MODULES "" CACHE STRING
135:        "Extra 'RegName=CInitSuffix'   …[truncated]
Fable
thinking
I'm examining how the inittab generator integrates numpy through the build configuration, specifically looking at how EXTRA_PY_MODULES and EXTRA_LINK_LIBS cache values are set up.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Main/CMakeLists.txt", "offset": 80, "limit": 160}
tool result
80	    if(BUILD_START)
81	        list(APPEND FREECAD_WASM_PY_GUI_MODULES StartGui)
82	    endif()
83	    if(NOT BUILD_GUI)
84	        set(FREECAD_WASM_PY_GUI_MODULES "")
85	    endif()
86	
87	    function(freecad_wasm_generate_inittab outfile)
88	        set(_decls "")
89	        set(_regs "")
90	        foreach(_mod IN LISTS ARGN)
91	            # An entry may be "RegName=CInitSuffix" to decouple the Python import
92	            # name (possibly dotted, e.g. PySide6.QtCore) from the C symbol
9  …[truncated]
Fable
⚙ Bash {"command": "cd /opt/toolchains/src/freecad-gui-build 2>/dev/null && grep -i \"EXTRA_PY_MODULES\\|EXTRA_LINK_LIBS\\|numpy\\|_coin\\|pivy\" CMakeCache.txt 2>/dev/null | head -40; echo \"zshexit ignore\"", "description": "Read configured cach…
tool result
//Check for pivy version using Python at build time
FREECAD_CHECK_PIVY:BOOL=ON
//Use system installed Coin and Pivy instead of the bundled versions.
FREECAD_USE_EXTERNAL_COIN_PIVY:BOOL=OFF
FREECAD_WASM_EXTRA_LINK_LIBS:STRING=-Wl,--start-group;/home/magik6k/lcad-wasm/pyside-port/build/m2-qtcore/libQtCore_wasm.a;/home/magik6k/lcad-wasm/pyside-port/build/qtgui/libQtGui_wasm.a;/home/magik6k/lcad-wasm/pyside-port/build/qtwidgets/libQtWidgets_wasm.a;/home/magik6k/lcad-wasm/pyside-port/build/libpyside/  …[truncated]
Fable
thinking
Now I'm diving into matplotlib's C-extension architecture to see which components need to be built statically and checking their dependencies—specifically looking at the core extensions like the path renderer, image processing, font handling with freetype, triangulation utilities, and the convex hull library.

The Agg backend is critical since it's used by Qt and other raster backends, and I need to account for supporting libraries like kiwisolver for layout constraints and contourpy for contour plotting. For image handling, Pillow is a runtime dependency for saving and loading images, but the Qt display path uses Agg's buffer directly without needing it, so it's not strictly required for ba  …
Fable
⚙ Bash {"command": "echo \"=== freetype in wasm toolchains ===\"; find /opt/toolchains -iname \"libfreetype*\" 2>/dev/null | head; echo \"=== pybind11 ===\"; find /opt/toolchains -iname \"pybind11\" -maxdepth 6 -type d 2>/dev/null | head; echo \"=…
tool result
Exit code 1
=== freetype in wasm toolchains ===
/opt/toolchains/oscad-deps/lib/libfreetype.a
/opt/toolchains/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten/libfreetype.a
/opt/toolchains/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten/libfreetype-legacysjlj.a
=== pybind11 ===
=== qhull ===
=== host matplotlib version ===
3.10.9
(eval):1: no matches found: /opt/toolchains/python-wasm/bin/python3*
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
⚙ Bash {"command": "echo \"=== who imports Plot / matplotlib in tree ===\"; grep -rl \"import Plot\\b\\|from Plot\\|import matplotlib\\|Plot workbench\" /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod --include=*.py 2>/dev/null | grep -v \"/P…
tool result
=== who imports Plot / matplotlib in tree ===
(eval):1: no matches found: --include=*.py
=== FindMatplotlib usage ===
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I've got freetype available through the emscripten sysroot and oscad-deps, which is good. Now I need to search the codebase to see which modules like TechDraw are importing matplotlib, and I should verify what version of CPython we're using for WebAssembly.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Mod && grep -rl \"import matplotlib\\|from matplotlib\\|import Plot\" --include=\"*.py\" . 2>/dev/null | grep -v \"^./Plot/\" | head -30; echo \"zshexit ignore\"", "descriptio…
tool result
AddonManager/Addon.py
Fem/femviewprovider/view_post_histogram.py
Fem/femviewprovider/view_post_lineplot.py
Fem/femtaskpanels/task_result_mechanical.py
PartDesign/WizardShaft/ShaftDiagram.py
Plot/Plot.py
zshexit ignore
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
⚙ Bash {"command": "ls /opt/toolchains/python-wasm/lib/ | grep -i \"python3\\|site\" | head; echo \"=== cpython ver ===\"; ls -d /opt/toolchains/python-wasm/lib/python3.* 2>/dev/null; echo \"=== emscripten libpng/jpeg anywhere ===\"; find /opt/too…
tool result
libpython3.14.a
python3.14
python3.14.zip
=== cpython ver ===
/opt/toolchains/python-wasm/lib/python3.14
/opt/toolchains/python-wasm/lib/python3.14.zip
=== emscripten libpng/jpeg anywhere ===
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I'm confirming that CPython 3.14 with matplotlib enables the PartDesign shaft wizard diagram and Plot module, and now I'm checking matplotlib 3.10's C/C++ extensions to ensure accuracy, starting with the _c_intern extension.

Looking at the full extension list for matplotlib 3.10, I see it uses pybind11 for most extensions like _path, _image, ft2font, _tri, and _qhull, with some bundled dependencies like agg headers and qhull. The build also requires numpy and vendored agg and qhull libraries.

Since matplotlib 3.9+, the build switched to meson-python with pybind11 (header-only), and contourpy also uses pybind11 while kiwisolver uses cppy—all header-only C++ helpers that compile cleanly. For  …
Fable
I have enough to produce the assessment. Let me confirm the matplotlib 3.10 extension set and its build system quickly.
Fable
⚙ Bash {"command": "python3 -c \"import matplotlib, os; d=os.path.dirname(matplotlib.__file__); import glob; print('\\n'.join(sorted(glob.glob(d+'/*.so')+glob.glob(d+'/backends/*.so'))))\" 2>/dev/null; echo \"=== kiwi/contourpy exts on host ===\";…
tool result
/usr/lib/python3.14/site-packages/matplotlib/_c_internal_utils.cpython-314-x86_64-linux-gnu.so
/usr/lib/python3.14/site-packages/matplotlib/_image.cpython-314-x86_64-linux-gnu.so
/usr/lib/python3.14/site-packages/matplotlib/_path.cpython-314-x86_64-linux-gnu.so
/usr/lib/python3.14/site-packages/matplotlib/_qhull.cpython-314-x86_64-linux-gnu.so
/usr/lib/python3.14/site-packages/matplotlib/_tri.cpython-314-x86_64-linux-gnu.so
/usr/lib/python3.14/site-packages/matplotlib/backends/_backend_agg.cpyth  …[truncated]
Fable
thinking
Looking at the C extensions available in the host matplotlib installation, I see there are 9 total across matplotlib, kiwisolver, and contourpy, with PIL being imported at pyplot initialization time.

Since matplotlib.image imports PIL.Image at the module level in version 3.10, Pillow becomes a hard dependency for matplotlib to even import — this means I need to build Pillow's _imaging extension with at least zlib support, or alternatively patch matplotlib.image to lazy-load PIL only when actually needed. The pragmatic approach would be a one-line patch to defer the PIL import, which would allow basic plotting without Pillow, though saving to PNG would still require it. Let me verify whether  …
Fable
⚙ Bash {"command": "python3 -c \"import matplotlib,os;print(os.path.dirname(matplotlib.__file__))\" 2>/dev/null | { read d; grep -n \"from PIL\\|import PIL\" \"$d/image.py\" \"$d/pyplot.py\" 2>/dev/null | head; }; echo \"=== Pillow C exts ===\"; p…
tool result
/usr/lib/python3.14/site-packages/matplotlib/pyplot.py:94:    import PIL.Image
/usr/lib/python3.14/site-packages/matplotlib/image.py:13:import PIL.Image
/usr/lib/python3.14/site-packages/matplotlib/image.py:14:import PIL.PngImagePlugin
/usr/lib/python3.14/site-packages/matplotlib/image.py:1699:    # The supported rawmodes are from PIL.PngImagePlugin._MODES.  When
=== Pillow C exts ===
/usr/lib/python3.14/site-packages/PIL/_avif.cpython-314-x86_64-linux-gnu.so
/usr/lib/python3.14/site-packages/PI  …[truncated]
Fable
thinking
So matplotlib's pyplot imports image.py at the module level, which in turn imports PIL.Image directly—meaning Pillow is a hard dependency just to import pyplot. That means I need to ensure Pillow's _imaging extension (and optionally _imagingft) are included in the C extension build list, since PIL.Image won't work without at least _imaging present.

The realistic build target is four packages: matplotlib, kiwisolver, contourpy, and Pillow. That gives me roughly 10 C extensions total—7 from matplotlib, 1 each from kiwisolver and contourpy, and at minimum 1 from Pillow (_imaging), though realistically 2 (_imaging and _imagingmath). The other Pillow extensions like _imagingft, _imagingcms, and   …
Fable
I have everything needed for the assessment.
Fable
⚙ StructuredOutput {"area": "Plot workbench + matplotlib (src/Mod/Plot)", "verdict": "tractable-with-work", "effortHours": "24-40h", "valueToUsers": "medium", "rootBlockers": ["No hard wall — every required C-extension is C/C++ built from source (mostly pybin…
tool result
Structured output provided successfully