subagent transcript

session 18e25685 · workflow wf_23df5b1c
← 18e25685 · archive
delegated task
Review the toolchain for reproducibility and correctness. List and read the build scripts: `ls -la /opt/toolchains/*.sh /home/magik6k/lcad-wasm/freeca
▸ Magik
Review the toolchain for reproducibility and correctness. List and read the build scripts: `ls -la /opt/toolchains/*.sh /home/magik6k/lcad-wasm/freecad-port/toolchain/` then read /home/magik6k/lcad-wasm/freecad-port/toolchain/configure-stage2.sh, /opt/toolchains/rebuild-deps-wasmeh.sh, /opt/toolchains/rebuild-deps-jseh.sh, /opt/toolchains/rebuild-qt-asyncify-412.sh, /opt/toolchains/fix-freetype-sjlj.sh, and /home/magik6k/lcad-wasm/freecad-port/toolchain/versions.lock if present. Assess: is the CURRENT shipping config (ASYNCIFY + JS-EH, emsdk 4.0.12, qt-asyncify, JS-EH deps) captured reproducibly? Are there hardcoded paths, missing steps, or scripts left in an inconsistent state from the many pivots? Is the getPyEMTrampolinePtr->0 patch baked into the build or only applied manually to a deployed FreeCAD.js (fragile)? Report findings + reproducibility gaps.
Fable
thinking
I'll start by examining the build scripts to understand what's available.
Fable
I'll start by listing the build scripts and reading them.
Fable
⚙ Bash {"command": "ls -la /opt/toolchains/*.sh /home/magik6k/lcad-wasm/freecad-port/toolchain/ 2>&1", "description": "List toolchain build scripts"}
tool result
-rw-r--r-- 1 agent agent 1128 Jul  4 03:04 /opt/toolchains/fix-freetype-sjlj.sh
-rwxr-xr-x 1 agent agent 3834 Jul  3 18:54 /opt/toolchains/rebuild-deps-407.sh
-rw-r--r-- 1 agent agent 5266 Jul  4 04:56 /opt/toolchains/rebuild-deps-jseh.sh
-rwxr-xr-x 1 agent agent 5578 Jul  4 05:43 /opt/toolchains/rebuild-deps-wasmeh.sh
-rw-r--r-- 1 agent agent 2688 Jul  4 06:19 /opt/toolchains/rebuild-qt-asyncify-412.sh
-rwxr-xr-x 1 agent agent 1530 Jul  3 21:52 /opt/toolchains/rebuild-qt-asyncify.sh
-rw-r--r--   …[truncated]
Fable
Let me read all the required files.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/toolchain/configure-stage2.sh"}
tool result
1	#!/usr/bin/env bash
2	# Stage 2/3: configure the full FreeCAD GUI (BUILD_GUI=ON) for wasm, linked
3	# against the asyncify Qt (qt-asyncify) so QEventLoop::exec() works.
4	set -euo pipefail
5	
6	TC=/opt/toolchains
7	SRC="$(cd "$(dirname "$0")/../FreeCAD" && pwd)"
8	BUILD="${1:-$TC/src/freecad-gui-build}"
9	PYWASM=$TC/python-wasm
10	QTDIR=$TC/qt-asyncify/6.11.1/wasm_singlethread   # asyncify-enabled Qt (source-built)
11	QTHOST=$TC/qt/6.11.1/gcc_64                       # host tools (moc/rcc/uic/  …[truncated]
Fable
⚙ Read {"file_path": "/opt/toolchains/rebuild-deps-wasmeh.sh"}
tool result
1	#!/usr/bin/env bash
2	# Rebuild all C++ deps with NATIVE wasm exceptions for the JSPI build.
3	# emsdk 4.0.12 with WASM_LEGACY_EXCEPTIONS=false (new EH / try_table) is the
4	# toolchain default, so -fwasm-exceptions here produces new-EH objects — needed
5	# because Binaryen 123 cannot parse OCCT's deeply-nested LEGACY-EH functions.
6	# C deps (CPython, ports) are exception-neutral and untouched.
7	set -e
8	TC=/opt/toolchains
9	export PATH="$TC/emsdk:$TC/emsdk/upstream/emscripten:$TC/emsdk/node  …[truncated]
Fable
⚙ Read {"file_path": "/opt/toolchains/rebuild-deps-jseh.sh"}
tool result
1	#!/usr/bin/env bash
2	# Rebuild all C++ deps with JS exceptions (-fexceptions) for the JSPI+JS-EH build.
3	# emsdk 4.0.12 with WASM_LEGACY_EXCEPTIONS=false (new EH / try_table) is the
4	# toolchain default, so -fwasm-exceptions here produces new-EH objects — needed
5	# because Binaryen 123 cannot parse OCCT's deeply-nested LEGACY-EH functions.
6	# C deps (CPython, ports) are exception-neutral and untouched.
7	set -e
8	TC=/opt/toolchains
9	export PATH="$TC/emsdk:$TC/emsdk/upstream/emscripten:$T  …[truncated]
Fable
⚙ Read {"file_path": "/opt/toolchains/rebuild-qt-asyncify-412.sh"}
tool result
1	#!/usr/bin/env bash
2	# Rebuild Qt with ASYNCIFY + JS-EH (-fexceptions). Uses the already-downloaded,
3	# gate-patched qtsrc. JS-EH avoids the Binaryen parse bug on OCCT's wasm-EH
4	# try_table output while JSPI still fixes the CPython-trampoline conflict.
5	set -e
6	TC=/opt/toolchains
7	source $TC/emsdk/emsdk_env.sh 2>/dev/null
8	QTHOST=$TC/qt/6.11.1/gcc_64
9	PREFIX=$TC/qt-asyncify/6.11.1/wasm_singlethread
10	rm -rf $TC/qt-asyncify $TC/qtsrc/qtbase-build $TC/qtsrc/qtsvg-build $TC/qtsrc/qttool  …[truncated]
Fable
⚙ Read {"file_path": "/opt/toolchains/fix-freetype-sjlj.sh"}
tool result
1	#!/usr/bin/env bash
2	# The emscripten freetype port ships two variants:
3	#   libfreetype.a               -> SUPPORT_LONGJMP=emscripten (legacy JS longjmp)
4	#   libfreetype-legacysjlj.a    -> SUPPORT_LONGJMP=wasm       (native __wasm_longjmp)
5	# Our JSPI build links with -fwasm-exceptions and Qt forces SUPPORT_LONGJMP=wasm,
6	# so it needs the wasm-longjmp variant. But FreeCAD/Coin/Qt find freetype via an
7	# explicit CMake path (FindFreetype -> sysroot libfreetype.a), which bypasses
8	# em  …[truncated]
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/toolchain/versions.lock"}
tool result
1	# FreeCAD wasm port — pinned toolchain (Stage 0)
2	# Decision log: see stage-0 notes. All deps must build with the same emsdk.
3	
4	emsdk        = 4.0.7        # Qt 6.11.1's EXACT pin. Lesson learned: emscripten broke the
5	                            # embind/emval JS ABI between 4.0.7 and 4.0.12 (legacy emval
6	                            # calls removed ~4.0.9) — Qt's prebuilt objects reference the
7	                            # old ABI, so "newer emsdk + older Qt archives" does NOT hold.
  …[truncated]
Fable
thinking
I need to dig into the patches directory, check what's actually deployed in FreeCAD.js, verify which emsdk version is running, and trace through how the final build gets linked together—particularly whether that getPyEMTrampolinePtr patch is baked into the build or applied manually.
Fable
Now let me investigate the emsdk version, patches, the getPyEMTrampolinePtr patch, and the link step.
Fable
⚙ Bash {"command": "cat /opt/toolchains/emsdk/.emscripten 2>/dev/null; echo \"---EMSDK VERSION---\"; cat /opt/toolchains/emsdk/upstream/emscripten/emscripten-version.txt 2>/dev/null; echo \"---ACTIVE---\"; cat /opt/toolchains/emsdk/emsdk_env.sh >/…
tool result
import os
emsdk_path = os.path.dirname(os.getenv('EM_CONFIG')).replace('\\', '/')
NODE_JS = emsdk_path + '/node/22.16.0_64bit/bin/node'
LLVM_ROOT = emsdk_path + '/upstream/bin'
BINARYEN_ROOT = emsdk_path + '/upstream'
EMSCRIPTEN_ROOT = emsdk_path + '/upstream/emscripten'
---EMSDK VERSION---
"4.0.12"
---ACTIVE---
-rw-r--r-- 1 agent agent 9 Jul  4 04:42 /opt/toolchains/emsdk/upstream/emscripten/emscripten-version.txt
---released list---
Fable
⚙ Bash {"command": "ls -la /home/magik6k/lcad-wasm/freecad-port/toolchain/patches/; echo \"===\"; ls -la /home/magik6k/lcad-wasm/freecad-port/; echo \"=== search getPyEMTrampolinePtr ===\"; grep -rl \"getPyEMTrampolinePtr\" /home/magik6k/lcad-wasm…
tool result
total 0
drwxr-xr-x 1 agent agent  76 Jul  3 19:34 .
drwxr-xr-x 1 agent agent 244 Jul  4 06:19 ..
-rw-r--r-- 1 agent agent   0 Jul  3 19:34 cpython-3.14.4-wasm-static-embed.patch
===
total 52
drwxr-xr-x 1 agent agent   550 Jul  4 06:46 .
drwxr-xr-x 1 agent agent   802 Jul  4 06:45 ..
-rw-r--r-- 1 agent agent 10238 Jul  3 18:00 00-OVERVIEW.md
drwxr-xr-x 1 agent agent   616 Jul  3 18:27 FreeCAD
-rw-r--r-- 1 agent agent  7241 Jul  4 06:46 STATUS.md
drwxr-xr-x 1 agent agent   238 Jul  4 06:45 deploy-  …[truncated]
Fable
thinking
Looking into the trampoline patch implementation—I need to examine how getPyEMTrampolinePtr is being handled across the CMakeLists configuration, the emscripten_trampoline.c file, and compare the deployed FreeCAD.js against the built version to understand what's different. The STATUS.md and research documentation should clarify the key details around this patch.
Fable
⚙ Bash {"command": "echo \"=== Main/CMakeLists.txt getPyEMTrampolinePtr context ===\"; grep -n \"getPyEMTrampolinePtr\\|Trampoline\\|trampoline\\|EM_JS\\|--post-js\\|post-js\\|jseh\\|asyncify\\|ASYNCIFY\\|JSPI\\|jspi\" /home/magik6k/lcad-wasm/free…
tool result
=== Main/CMakeLists.txt getPyEMTrampolinePtr context ===
75:        # ASYNCIFY + JS-EH build (see research/R10). This is the only combination
79:        #  * JSPI is out: JS-EH's invoke_* frames can't be suspended across; and
80:        #    wasm-EH is invalid. ASYNCIFY instruments the whole module so any
82:        #  * CPython's wasm-gc trampoline crashes under asyncify, so we force the
83:        #    JS trampoline (getPyEMTrampolinePtr->0, applied post-link). It's
84:        #    asyncify-sa  …[truncated]
Fable
⚙ Bash {"command": "echo \"=== emscripten_trampoline.c getPyEMTrampolinePtr ===\"; grep -n \"getPyEMTrampolinePtr\\|EMSCRIPTEN_SUPPORTS_JSPI\\|__EMSCRIPTEN_major\\|return 0\\|WebAssembly.Function\" /opt/toolchains/src/Python-3.14.4/Python/emscript…
tool result
=== emscripten_trampoline.c getPyEMTrampolinePtr ===
57:function getPyEMTrampolinePtr() {
69:        return 0;
77:        return 0;
91:    const ptr = getPyEMTrampolinePtr();
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Main/CMakeLists.txt", "offset": 60, "limit": 180}
tool result
60	    freecad_wasm_generate_inittab(${CMAKE_CURRENT_BINARY_DIR}/WasmInittab.cpp
61	        ${FREECAD_WASM_PY_MODULES})
62	    freecad_wasm_generate_inittab(${CMAKE_CURRENT_BINARY_DIR}/WasmInittabGui.cpp
63	        ${FREECAD_WASM_PY_MODULES} ${FREECAD_WASM_PY_GUI_MODULES})
64	
65	    set(FREECAD_WASM_EXTRA_LINK_LIBS "" CACHE STRING
66	        "Extra static archives appended to the FreeCAD wasm links")
67	    set(FREECAD_WASM_COMMON_LINK_OPTIONS
68	        "-sALLOW_MEMORY_GROWTH=1"
69	        "-s  …[truncated]
Fable
thinking
The patch gets applied after linking rather than being baked into the build itself, which is what creates the fragility here. I need to check whether there's an automated script handling this or if it's a manual step, and compare the deployed FreeCAD.js against the built version to understand the actual state.
Fable
⚙ Bash {"command": "echo \"=== getPyEMTrampolinePtr in built vs deployed ===\"; for f in /opt/toolchains/src/freecad-gui-build/bin/FreeCAD.js /opt/toolchains/freecad-gui-web/FreeCAD.js /home/magik6k/lcad-wasm/freecad-port/deploy-gui/FreeCAD.js /ho…
tool result
=== getPyEMTrampolinePtr in built vs deployed ===
--- /opt/toolchains/src/freecad-gui-build/bin/FreeCAD.js
function getPyEMTrampolinePtr(){return 0;let isIOS=globalThis.navigator&&(/iPad|iPhone|iPod/.test(navigator.userAgent)||navigator.platform==="MacIntel"&&typeof navigator.maxTouchPoints!=="undefined"&&navigator.maxTouchPoints>1);if(isIOS){return 0
1
--- /opt/toolchains/freecad-gui-web/FreeCAD.js
2
--- /home/magik6k/lcad-wasm/freecad-port/deploy-gui/FreeCAD.js
function getPyEMTrampolinePtr(){  …[truncated]
Fable
⚙ Bash {"command": "echo \"=== deploy-gui contents ===\"; ls -la /home/magik6k/lcad-wasm/freecad-port/deploy-gui/ /opt/toolchains/freecad-gui-web/ 2>/dev/null; echo \"=== any deploy/build/patch scripts referencing trampoline ===\"; grep -rn \"getP…
tool result
<persisted-output>
Output too large (514.1KB). Full output saved to: /home/agent/.claude/projects/-home-magik6k-lcad-wasm/18e25685-98b5-4959-935f-943b1af20789/tool-results/b2krb6ghe.txt

Preview (first 2KB):
=== deploy-gui contents ===
/home/magik6k/lcad-wasm/freecad-port/deploy-gui/:
total 199784
drwxr-xr-x 1 agent agent       276 Jul  4 12:31 .
drwxr-xr-x 1 agent agent       550 Jul  4 06:46 ..
-rw-r--r-- 1 agent agent    523223 Jul  4 06:38 FreeCAD.js
-rwxr-xr-x 1 agent agent 188416217 Jul  4  …[truncated]
Fable
thinking
I'm noticing that the built FreeCAD.js file at the build output path already contains the `return 0;` statement in getPyEMTrampolinePtr, which is puzzling since the comment indicates the patch should be applied post-link. I need to figure out whether this got baked in during the build process itself or if someone manually added it.

The key is checking the source—getPyEMTrampolinePtr is a JavaScript function that comes from Python's emscripten_trampoline.c file, which uses EM_JS to define it. If the source C file already has `return 0;` compiled into it, then it's baked in at the source level rather than patched afterward.
Fable
⚙ Read {"file_path": "/opt/toolchains/src/Python-3.14.4/Python/emscripten_trampoline.c", "offset": 45, "limit": 55}
tool result
45	                                    PyCFunctionWithKeywords func,
46	                                    PyObject* self,
47	                                    PyObject* args,
48	                                    PyObject* kw);
49	
50	/**
51	 * Backwards compatible trampoline works with all JS runtimes
52	 */
53	EM_JS(PyObject*, _PyEM_TrampolineCall_JS, (PyCFunctionWithKeywords func, PyObject *arg1, PyObject *arg2, PyObject *arg3), {
54	    return wasmTable.get(func)(arg1, arg2, arg3);
55	}  …[truncated]
Fable
thinking
The source file `emscripten_trampoline.c` hasn't been patched—`getPyEMTrampolinePtr()` still has its original implementation starting with `let isIOS = ...` at line 61. But the built FreeCAD.js file contains `return 0;` injected at the start of that function, which means the modification was added during the build process rather than in the source.

This is a post-link patch applied after emscripten generated the JavaScript, not baked into the build itself. If I re-run ninja, it would regenerate FreeCAD.js without the patch since the source `.c` file doesn't contain it. I need to verify whether any build automation actually applies this patch, check the timestamps to confirm the build-tree o  …
Fable
Key finding emerging: the source `emscripten_trampoline.c` (line 57-83) is UNPATCHED, yet the built `FreeCAD.js` has `return 0;` injected. Let me confirm no script applies it and check STATUS/R10 docs and installed deps.
Fable
⚙ Bash {"command": "echo \"=== any script/sed that injects return 0 into getPyEMTrampolinePtr anywhere ===\"; grep -rn \"getPyEMTrampolinePtr\\|TrampolinePtr(){return 0\\|Trampoline.*return 0\" /opt/toolchains/*.sh /home/magik6k/lcad-wasm/freecad-…
tool result
=== any script/sed that injects return 0 into getPyEMTrampolinePtr anywhere ===
/home/magik6k/lcad-wasm/freecad-port/STATUS.md:22:  (`getPyEMTrampolinePtr→0`, baked post-link). Valid module, GUI renders,
/home/magik6k/lcad-wasm/freecad-port/research/R10-eh-jspi-asyncify-findings.md:20:     `getPyEMTrampolinePtr()` returns 0 (iOS path, or any thrown error).
/home/magik6k/lcad-wasm/freecad-port/research/R10-eh-jspi-asyncify-findings.md:40:**ASYNCIFY + JS-EH + force the JS trampoline** (`getPyEMTra  …[truncated]
Fable
thinking
I'm realizing there's a critical reproducibility issue: the getPyEMTrampolinePtr→0 patch that's manually baked into FreeCAD.js has no automation behind it. When the build regenerates FreeCAD.js from scratch via `ninja FreeCADMain`, the patch disappears, which breaks the asyncify trampoline. The build artifacts show the patch is present, but there's no script or sed command actually applying it—it was just hand-edited into the generated file.

Let me check STATUS.md and the R10 configuration to see if there's a documented patch step I'm missing, and verify the dependency build flags are consistent across configure-stage2 and rebuild-deps-jseh.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/STATUS.md"}
tool result
1	# FreeCAD wasm port — execution status
2	
3	Updated: 2026-07-04 (session 2)
4	
5	## Headline
6	**FreeCAD's full Qt GUI runs in a browser AND Python now drives the OCCT kernel
7	from the live module** — the two were previously mutually exclusive. The GUI
8	renders (menus, Start workbench "Welcome" with theme thumbnails, Report View,
9	modal dialogs) and `Part.makeBox(10,10,10).Volume → 1000` runs with no trampoline
10	crash. Screenshot: `deploy-gui/boot-async.png`. The 3D viewport still needs t  …[truncated]
Fable
thinking
I'm noticing a discrepancy between what STATUS.md claims are in the reproducibility section and where those files actually live—specifically, `rebuild-deps-407.sh` and `rebuild-qt-asyncify.sh` are listed as being in `toolchain/` but they're actually located in `/opt/toolchains/`.

The bigger issue is that `versions.lock` is stale and doesn't reflect the current shipping configuration: it pins emsdk to 4.0.7 based on an old rationale about prebuilt Qt compatibility, but the system is now running emsdk 4.0.12 with source-built Qt via qt-asyncify, making that original concern irrelevant. The lock file also doesn't capture the JS-EH dependencies, the trampoline patch, or asyncify itself—it's doc  …
Fable
STATUS.md gives me the intended config. Let me verify a few concrete correctness points: the freetype variant currently in the sysroot, and whether the deps-jseh ICU inconsistency and DEPS-WASMEH-OK tag are real.
Fable
⚙ Bash {"command": "C=/opt/toolchains/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten\necho \"=== current sysroot libfreetype.a longjmp variant ===\"; cd /tmp && rm -f ftbase.c.o; emar x \"$C/libfreetype.a\" ftbase.c.o 2>/dev/null &&…
tool result
=== current sysroot libfreetype.a longjmp variant ===
         U emscripten_longjmp
=== sizes: base vs legacysjlj vs (are they identical now?) ===
-rw-r--r-- 1 agent agent 3931466 Jul  4 05:47 /opt/toolchains/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten/libfreetype-legacysjlj.a
-rw-r--r-- 1 agent agent 3931342 Jul  4 06:31 /opt/toolchains/emsdk/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten/libfreetype.a
32cf8785efc3d474c5e8ed07eb7de26a  /opt/toolchains/emsdk/upstream/e  …[truncated]
Fable
thinking
The sysroot's libfreetype.a is using the legacy JS longjmp variant, which is correct for the current asyncify and exception handling setup. The base library differs from the legacy SJLJ version, confirming that the fix script hasn't overwritten it yet.

However, fix-freetype-sjlj.sh is a destructive leftover from the JSPI pivot that would break the current build if run—it would replace the correct variant with the wasm-longjmp one, causing undefined symbol errors. Since the base freetype was regenerated at 06:31 via embuilder with the right variant, the script is now stale and dangerous.

Both dependency scripts echo the same `DEPS-WASMEH-OK` string, so a build orchestrator can't distinguish  …
Fable
I have enough to assess. Let me compile the findings. Confirmed facts: - Active emsdk is 4.0.12 (`emscripten-version.txt` = "4.0.12"), but `versions.lock` pins `emsdk = 4.0.7`. - Source `emscripten_trampoline.c:57` is UNPATCHED (`function getPyEMTrampolinePtr() {` with original body), yet built/deployed `FreeCAD.js` have `return 0;` injected as first statement — no script does this. - Current sysroot `libfreetype.a` = emscripten-longjmp variant (correct for JS-EH); differs from the `-legacysjlj` variant, so `fix-freetype-sjlj.sh` is NOT currently applied. - Both `rebuild-deps-jseh.sh` and `rebuild-deps-wasmeh.sh` echo `DEPS-WASMEH-OK`; jseh's ICU uses `--with-cross-build=$TC/src/icu/source` (source dir) with no native build, which wasmeh's own comment documents as wrong.
Fable
⚙ StructuredOutput {"findings": [{"severity": "high", "category": "reproducibility-trampoline-patch", "summary": "The load-bearing getPyEMTrampolinePtr->0 fix is a manual hand-edit of the GENERATED FreeCAD.js, not baked into the build; a clean relink silently…
tool result
Structured output provided successfully