subagent transcript

session 17f09f89 · workflow wf_7338a73f
← 17f09f89 · archive
delegated task
MISSION: push the FreeCAD->WebAssembly port from its current state toward the ~80% browser-parity ceiling in one coordinated effort. You are ONE agent
▸ Magik
MISSION: push the FreeCAD->WebAssembly port from its current state toward the ~80% browser-parity ceiling in one coordinated effort. You are ONE agent in a parallel swarm; do ONLY your assigned slice and return a precise spec the integrator will apply. The integrator (main loop) owns the single shared FreeCAD cmake reconfigure + ninja build + link; YOU DO NOT run the FreeCAD build. TOOLCHAIN / ENV: run `source /home/magik6k/lcad-wasm/env.sh` first (sets emsdk 4.0.12 + EM_CONFIG + the libclang-21->22 shim). Tools: emcc/em++/emar/emnm, host swig 4.4.1, host python 3.14, cmake, ninja. Constraints: emscripten single-thread (NO pthreads, QT_FEATURE_thread=-1), NO dlopen (static inittab), NO subprocess/QProcess, ASYNCIFY + JS-exceptions, static CPython 3.14 + Qt 6.11.1 asyncify + OCCT + Coin3D. `-lidbfs.js` is ALREADY in the link options. PATHS: - FreeCAD source (git repo, branch wasm-parity-push): /home/magik6k/lcad-wasm/freecad-port/FreeCAD (src/Mod/<WB>, src/Gui, src/App, src/3rdParty, src/Main/CMakeLists.txt) - wasm build tree: /opt/toolchains/src/freecad-gui-build (CMakeCache.txt, build.ninja) — READ ONLY for you; do not build here. - deploy: /home/magik6k/lcad-wasm/freecad-port/deploy (index.html, boot.py, *.data). Working M3 build is backed up in deploy-m3-backup/. - pyside-port build dir for sublib archives: /home/magik6k/lcad-wasm/pyside-port/build/<name> - Qt asyncify wasm: /opt/toolchains/qt-asyncify/6.11.1/wasm_singlethread ; python-wasm: /opt/toolchains/python-wasm (include/python3.14, lib) ; ICU: /opt/toolchains/icu-wasm HOW MODULES GET ENABLED (the proven pipeline — return these as DATA, do not edit the shared files yourself except your own module's source): 1. Cache flag: BUILD_<WB>=ON (cmake -D). Enabling it makes src/Mod/<WB>/CMakeLists build the <WB> and <WB>Gui STATIC libs (top-level CMakeLists.txt:91-107 rewrites SHARED/MODULE->STATIC under EMSCRIPTEN). In-tree 3rdParty deps (libE57Format, OndselSolver, libarea, Coin) build within this same tree when their consuming module is enabled. 2. inittab + link: the integrator adds a block to src/Main/CMakeLists.txt of the form if(BUILD_MESH) list(APPEND FREECAD_WASM_PY_MODULES Mesh) list(APPEND FREECAD_WASM_PY_GUI_MODULES MeshGui) endif() FREECAD_WASM_PY_MODULES entries are BOTH registered in the inittab (PyImport_AppendInittab("<name>", PyInit_<name>)) AND linked. Some modules build "_<Name>.a" and register the dotted/underscore name (e.g. PartDesign target -> _PartDesign, PartDesign/__init__.py does 'import _PartDesign'). Determine the exact PyInit symbol + registered name for YOUR module by reading its App/Gui CMakeLists (OUTPUT_NAME / target name) and its Init.py/__init__.py import. 3. External prebuilt archives (only pivy._coin) go in FREECAD_WASM_EXTRA_LINK_LIBS (a -Wl,--start-group;...;-Wl,--end-group list) + an inittab entry via FREECAD_WASM_EXTRA_PY_MODULES ("RegName=CInitSuffix", e.g. "PySide6.QtCore=QtCore"). 4. Python trees: modules ship a Python workbench tree (src/Mod/<WB>/*.py, InitGui.py) that must be packaged onto the wasm FS at /freecad/Mod/<WB> via emscripten file_packager into a supplementary .data loaded by index.html. List the tree path + mount; the integrator packs it. Current live inittab modules: Import,ImportGui,Materials,MatGui,Measure,MeasureGui,Part,PartGui,_PartDesign,PartDesignGui,Sketcher,SketcherGui,Spreadsheet,SpreadsheetGui,StartGui,Surface,SurfaceGui + PySide6.QtCore/QtGui/QtWidgets=QtCore/QtGui/QtWidgets + shiboken6.Shiboken=Shiboken. Current FREECAD_WASM_EXTRA_PY_MODULES: "shiboken6.Shiboken=Shiboken;PySide6.QtCore=QtCore;PySide6.QtGui=QtGui;PySide6.QtWidgets=QtWidgets". SINGLE-THREAD PATCHING: QtConcurrent/QThreadPool/std::async/std::thread do not work under QT_FEATURE_thread=-1. Convert to synchronous: QtConcurrent::blockingMapped(seq,fn)->serial std::transform; QtConcurrent::mapped -> serial loop; QtConcurrent::run(fn)+QFutureWatcher -> call fn() inline then invoke the finished handler directly. Preserve behavior. Patch ONLY your module's own source files (disjoint from other agents). Cite exact file:line. RETURN A PRECISE SPEC. Be concrete and evidence-based (grep/read the real files). Do NOT run the FreeCAD reconfigure/ninja. Apply source patches (Edit) only within your assigned files. YOUR SLICE — P0 browser persistence (Tier 0). Edit ONLY /home/magik6k/lcad-wasm/freecad-port/deploy/index.html. Today it uses ephemeral MEMFS — nothing survives reload. `-lidbfs.js` is already linked. Mount IDBFS over the FreeCAD user/config dir and Qt config so user.cfg + QSettings (window/toolbar layout) persist. In Module.preRun: create the persistent dirs (e.g. /home/web_user or the HOME the app uses — inspect index.html ENV: HOME=/tmp, FREECAD_HOME=/freecad; the FreeCAD user dir derives from HOME per App/Application.cpp), mount IDBFS there, and FS.syncfs(true, cb) to HYDRATE before FreeCAD init (the boot must WAIT for the async hydrate before createFreeCAD runs — restructure so createFreeCAD is called from the syncfs callback, or preRun adds a run dependency). Persist on save + beforeunload/visibilitychange via FS.syncfs(false). Pick the correct persistent mount points so BOTH FreeCAD user.cfg AND Qt QSettings survive. Keep the existing boot.py/data-loading flow working. Return the P0 spec (needsRebuild=false — index.html only). Provide a probe: write a value to FreeCAD prefs, note that after reload it should persist (describe the manual/automated check).
Fable
thinking
I'll start by examining the index.html file to see how the boot process is currently structured.
Fable
I'll start by reading the current index.html and understanding the boot flow.
Fable
⚙ Bash {"command": "cat /home/magik6k/lcad-wasm/freecad-port/deploy/index.html", "description": "Read deploy index.html"}
tool result
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>FreeCAD in your browser — WebAssembly</title>
<style>
  html, body { margin: 0; height: 100%; font-family: system-ui, "Segoe UI", sans-serif; background:#2b2b30; color:#eee; }
  #bar { position: fixed; top: 0; left: 0; right: 0; z-index: 20; display:flex; align-items:center; gap:12px;
         background:#1d1d21; border-bottom:1px solid #000; padding:6px 12  …[truncated]
Fable
⚙ Bash {"command": "ls -la /home/magik6k/lcad-wasm/freecad-port/deploy/", "description": "List deploy dir"}
tool result
total 337048
drwxr-xr-x 1 magik6k magik6k       578 Jul  5 13:33 .
drwxr-xr-x 1 magik6k magik6k       668 Jul  5 19:35 ..
-rw-r--r-- 1 magik6k magik6k       805 Jul  5 19:01 boot.py
-rw-r--r-- 1 magik6k magik6k  15229294 Jul  4 20:36 freecad.data
-rw------- 1 magik6k magik6k   8977277 Jul  4 20:36 freecad.data.gz
-rw-r--r-- 1 magik6k magik6k    135559 Jul  4 20:36 freecad.data.js
-rw------- 1 magik6k magik6k     17642 Jul  4 20:36 freecad.data.js.gz
-rw-r--r-- 1 magik  …[truncated]
Fable
thinking
I need to trace through FreeCAD's code to see how it determines the user configuration directory, particularly where user.cfg gets stored and how Qt's QSettings interact with the HOME and FREECAD_HOME environment variables.
Fable
Let me investigate how FreeCAD derives its user config dir from HOME and where Qt QSettings write.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -rn \"getUserAppDataDir\\|\\.FreeCAD\\|getUserConfigDir\\|user.cfg\\|mConfig\\[\\\"UserAppData\\\"\\]\\|UserHomePath\\|getHomePath\" src/App/Application.cpp | head -60", "…
tool result
src/App/Application.cpp:1411:std::string Application::getHomePath()
src/App/Application.cpp:1413:    return Base::FileInfo::pathToString(Application::directories()->getHomePath()) + PATHSEP;
src/App/Application.cpp:1464:std::string Application::getUserAppDataDir()
src/App/Application.cpp:1466:    return Base::FileInfo::pathToString(_appDirs->getUserAppDataDir()) + PATHSEP;
src/App/Application.cpp:2482:    ("user-cfg,u", boost::program_options::value<std::string>(),"User config file to load/save   …[truncated]
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/App/Application.cpp", "pages": "", "offset": 3478, "limit": 200}
tool result
<tool_use_error>Invalid pages parameter: "". Use formats like "1-5", "3", or "10-20". Pages are 1-indexed.</tool_use_error>
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/App/Application.cpp", "offset": 3478, "limit": 220}
tool result
3478	 * \brief findUserHomePath
3479	 * If the passed path name is not empty it will be returned, otherwise
3480	 * the user home path of the system will be returned.
3481	 */
3482	QString findUserHomePath(const QString& userHome)
3483	{
3484	    return userHome.isEmpty() ? getUserHome() : userHome;
3485	}
3486	
3487	/*!
3488	 * \brief findPath
3489	 * Returns the path where to store application files to.
3490	 * If \a customHome is not empty it will be used, otherwise a path starting from \a st  …[truncated]
Fable
thinking
I'm checking what Qt's standard paths resolve to on emscripten/wasm. Since it's using the Linux/Unix Qt build, the config location would be `$XDG_CONFIG_HOME` or `$HOME/.config`, and the data location would be `$XDG_DATA_HOME` or `$HOME/.local/share`. The subdirectories are then appended to these base paths.

To understand the actual runtime behavior, I need to look at what paths FreeCAD creates when it runs in this wasm environment—checking both the getSubDirectories and getUserHome functions to see what they return.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -n \"getSubDirectories\\|getUserHome\\|getOldDataLocation\\|GenericConfigLocation\\|GenericDataLocation\" src/App/Application.cpp | head", "description": "Find getSubDirec…
tool result
3388: * \brief getUserHome
3391:QString getUserHome()
3417: * \brief getOldGenericDataLocation
3422:QString getOldGenericDataLocation(QString home)
3440: * \brief getSubDirectories
3443:void getSubDirectories(std::map<std::string,std::string>& mConfig, std::vector<std::string>& appData)
3454: * \brief getOldDataLocation
3458:void getOldDataLocation(std::map<std::string,std::string>& mConfig, std::vector<std::string>& appData)
3473:    getSubDirectories(mConfig, appData);
3484:    return userHome  …[truncated]
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/App/Application.cpp", "offset": 3388, "limit": 90}
tool result
3388	 * \brief getUserHome
3389	 * Returns the user's home directory.
3390	 */
3391	QString getUserHome()
3392	{
3393	    QString path;
3394	#if defined(FC_OS_WASM)
3395	    // No passwd database in the wasm sandbox; $HOME comes from the embedder.
3396	    const char* home = std::getenv("HOME");
3397	    path = QString::fromUtf8(home ? home : "/tmp");
3398	#elif defined(FC_OS_LINUX) || defined(FC_OS_CYGWIN) || defined(FC_OS_BSD) || defined(FC_OS_MACOSX)
3399	    // Default paths for the user spe  …[truncated]
Fable
thinking
I'm looking at how FreeCAD derives its config and data paths from Qt's standard locations, using the vendor name "FreeCAD" and executable name "FreeCAD" as subdirectories. On Linux with Qt, this typically resolves to paths under `$XDG_DATA_HOME` and `$XDG_CONFIG_HOME`, falling back to `.local/share` and `.config` in the home directory if those environment variables aren't set.

The real challenge is figuring out what Qt's QStandardPaths actually returns in this WebAssembly build environment. Rather than guessing, I should check the actual runtime values—either by looking at what FreeCAD logs during startup, examining the boot.py file, or checking Qt's emscripten implementation directly. Qt's  …
Fable
⚙ Bash {"command": "find /opt/toolchains/qt-asyncify -name \"qstandardpaths*\" 2>/dev/null; echo \"---src---\"; find /opt/toolchains -path \"*corelib/io/qstandardpaths*\" 2>/dev/null | head", "description": "Find Qt qstandardpaths impl"}
tool result
/opt/toolchains/qt-asyncify/6.11.1/wasm_singlethread/include/QtCore/qstandardpaths.h
---src---
/opt/toolchains/qtsrc/qtbase/tests/auto/corelib/io/qstandardpaths
/opt/toolchains/qtsrc/qtbase/tests/auto/corelib/io/qstandardpaths/CMakeLists.txt
/opt/toolchains/qtsrc/qtbase/tests/auto/corelib/io/qstandardpaths/tst_qstandardpaths.cpp
/opt/toolchains/qtsrc/qtbase/src/corelib/io/qstandardpaths.cpp
/opt/toolchains/qtsrc/qtbase/src/corelib/io/qstandardpaths.h
/opt/toolchains/qtsrc/qtbase/src/corelib/io/q  …[truncated]
Fable
thinking
I'm checking whether emscripten falls back to the Unix implementation for standard paths and how it handles config locations with XDG or HOME environment variables.
Fable
⚙ Bash {"command": "grep -n \"XDG_CONFIG_HOME\\|XDG_DATA_HOME\\|XDG_CACHE_HOME\\|\\.config\\|\\.local/share\\|\\.cache\\|HomeLocation\\|qEnvironmentVariable\\|/\\.config\" /opt/toolchains/qtsrc/qtbase/src/corelib/io/qstandardpaths_unix.cpp | head …
tool result
177:    case HomeLocation:
189:            xdgCacheHome = qEnvironmentVariable("XDG_CACHE_HOME");
194:                xdgCacheHome = QDir::homePath() + "/.cache"_L1;
208:            xdgStateHome = qEnvironmentVariable("XDG_STATE_HOME");
227:            xdgDataHome = qEnvironmentVariable("XDG_DATA_HOME");
232:                xdgDataHome = QDir::homePath() + "/.local/share"_L1;
247:            xdgConfigHome = qEnvironmentVariable("XDG_CONFIG_HOME");
252:                xdgConfigHome = QDir::homePa  …[truncated]
Fable
thinking
With HOME set to /tmp, the configuration directories resolve to specific paths under that location, and I need to verify that QDir::homePath() actually reads the HOME environment variable under emscripten by checking the implementation around line 177.
Fable
⚙ Bash {"command": "sed -n '170,200p' /opt/toolchains/qtsrc/qtbase/src/corelib/io/qstandardpaths_unix.cpp; echo \"=== QDir homePath ===\"; grep -n \"homePath\\|QT_ENSURE_PARSED\\|HOME\" /opt/toolchains/qtsrc/qtbase/src/corelib/io/qdir.cpp | head",…
tool result
    return true;
}

QString QStandardPaths::writableLocation(StandardLocation type)
{
    switch (type) {
    case HomeLocation:
        return QDir::homePath();
    case TempLocation:
        return QDir::tempPath();
    case CacheLocation:
    case GenericCacheLocation:
    {
        QString xdgCacheHome;
        if (isTestModeEnabled()) {
            xdgCacheHome = QDir::homePath() + "/.qttest/cache"_L1;
        } else {
            // http://standards.freedesktop.org/basedir-spec/basedir-spe  …[truncated]
Fable
thinking
I'm checking how QFileSystemEngine handles the home path on emscripten by looking at the Unix implementation, which reads the HOME environment variable. With HOME set to /tmp, FreeCAD's configuration paths resolve to /tmp/.config/FreeCAD/FreeCAD/ for the user config directory, placing user.cfg at /tmp/.config/FreeCAD/FreeCAD/user.cfg, while UserAppData points to /tmp/.

local/share/FreeCAD/FreeCAD/, the cache goes to /tmp/.cache/FreeCAD/FreeCAD/Cache/, and macros are stored at /tmp/.local/share/FreeCAD/FreeCAD/Macro/. I need to verify what ExeVendor is actually set to and whether keepDeprecatedPaths is enabled, since these affect the final path structure.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -rn \"ExeVendor\\|KeepDeprecatedPaths\\|\\\"ExeName\\\"\\]\" src/App/Application.cpp | head; echo \"=== homePath unix ===\"; grep -n \"homePath\\|HOME\" /opt/toolchains/qt…
tool result
src/App/Application.cpp:1418:    return mConfig["ExeName"];
src/App/Application.cpp:2628:        str << mConfig["ExeName"] << " " << mConfig["ExeVersion"]
src/App/Application.cpp:2695:        mConfig["LoggingFileName"] = mConfig["UserAppData"] + mConfig["ExeName"] + ".log";
src/App/Application.cpp:2821:        parseProgramOptions(argc, argv, mConfig["ExeName"], vm);
src/App/Application.cpp:2825:        mConfig["KeepDeprecatedPaths"] = "1";
src/App/Application.cpp:2906:                             …[truncated]
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && sed -n '2818,2830p' src/App/Application.cpp; echo \"=== ExeVendor set where ===\"; grep -rn \"ExeVendor\" src/App/*.cpp src/Main/*.cpp src/Gui/*.cpp 2>/dev/null | grep -i \"=\\…
tool result
                mConfig["RunMode"] = "Cmd";
            }
        };
        parseProgramOptions(argc, argv, mConfig["ExeName"], vm);
    }

    if (vm.contains("keep-deprecated-paths")) {
        mConfig["KeepDeprecatedPaths"] = "1";
    }

    if (vm.contains("safe-mode")) {
        mConfig["SafeMode"] = "1";
    }
=== ExeVendor set where ===
src/Main/MainPy.cpp:84:    App::Application::Config()["ExeVendor"] = "FreeCAD";
src/Gui/MainWindow.cpp:2111:    QString vendor = QString::fromStdString(  …[truncated]
Fable
thinking
I need to trace through the WebAssembly build configuration to find the entry point — checking how the main function gets set up, looking at the inittab-based launcher, and understanding how FREECAD_WASM and the ExeVendor/ExeName variables determine which main gets used.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -rln \"EMSCRIPTEN\\|FREECAD_WASM\\|createFreeCAD\\|runApplication\" src/Main/ 2>/dev/null; echo \"=== ExeName/Vendor in Main ===\"; grep -rn 'ExeName\\|ExeVendor\\|KeepDep…
tool result
src/Main/MainCmd.cpp
src/Main/CMakeLists.txt
src/Main/MainGui.cpp
=== ExeName/Vendor in Main ===
src/Main/MainCmd.cpp:93:    App::Application::Config()["ExeName"] = "FreeCAD";
src/Main/MainCmd.cpp:94:    App::Application::Config()["ExeVendor"] = "FreeCAD";
src/Main/MainPy.cpp:83:    App::Application::Config()["ExeName"] = "FreeCAD";
src/Main/MainPy.cpp:84:    App::Application::Config()["ExeVendor"] = "FreeCAD";
src/Main/MainGui.cpp:266:    App::Application::Config()["ExeName"] = "FreeCAD";
  …[truncated]
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -n \"EMSCRIPTEN\\|createFreeCAD\\|FREECAD_USER\\|KeepDeprecated\\|main(\\|EMSCRIPTEN_KEEPALIVE\" src/Main/MainGui.cpp | head -30", "description": "Check MainGui wasm speci…
tool result
151:#ifdef __EMSCRIPTEN__
178:extern "C" EMSCRIPTEN_KEEPALIVE int freecad_run_python(const char* code)
195:int main(int argc, char** argv)
197:#ifdef __EMSCRIPTEN__
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Main/MainGui.cpp", "offset": 151, "limit": 130}
tool result
151	#ifdef __EMSCRIPTEN__
152	#include <QtGlobal>
153	#include <cstdio>
154	// Generated WasmInittabGui.cpp: registers statically linked Python extension
155	// modules (App + Gui) before the interpreter is initialized.
156	void freecadWasmRegisterInittab();
157	
158	// Qt-for-wasm's default message handler runs Qt's message-pattern formatter
159	// (qFormatLogMessage), which throws std::bad_variant_access on this build and
160	// aborts the app the first time QEventDispatcherWasm emits a qDebug  …[truncated]
Fable
thinking
With `AppDataSkipVendor` enabled, only the application name "FreeCAD" gets added to the subdirectories list, skipping the vendor directory. When HOME is set to /tmp without keeping deprecated paths, the user config path resolves to /tmp/.config/FreeCAD/, where the user.cfg file would be located.

The other standard paths follow the XDG convention: application data goes to /tmp/.local/share/FreeCAD/, and cache files to /tmp/.cache/FreeCAD/Cache/. For Qt's QSettings, FreeCAD would store window and toolbar layout information in a separate config file at /tmp/.config/FreeCAD/FreeCAD.conf, which Qt generates based on the organization and application names set in the QApplication instance.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -rn \"setOrganizationName\\|setApplicationName\\|setOrganizationDomain\\|QSettings\" src/Gui/Application.cpp src/Gui/MainWindow.cpp src/Main/MainGui.cpp | head -20", "desc…
tool result
src/Gui/Application.cpp:2550:        QApplication::setApplicationName(QString::fromUtf8(it->second.c_str()));
src/Gui/Application.cpp:2553:        QApplication::setApplicationName(QString::fromStdString(App::Application::getExecutableName()));
src/Gui/MainWindow.cpp:48:#include <QSettings>
src/Gui/MainWindow.cpp:2116:    QSettings config(vendor, application);
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Gui/MainWindow.cpp", "offset": 2100, "limit": 40}
tool result
2100	    QWidgetList toplevel = QApplication::topLevelWidgets();
2101	    for (const auto& it : toplevel) {
2102	        auto view = dynamic_cast<MDIView*>(it);
2103	        if (view) {
2104	            view->setCurrentViewMode(MDIView::Child);
2105	        }
2106	    }
2107	}
2108	
2109	void MainWindow::loadWindowSettings()
2110	{
2111	    QString vendor = QString::fromStdString(App::Application::Config()["ExeVendor"]);
2112	    QString application = QString::fromStdString(App::Application::get  …[truncated]
Fable
thinking
I'm looking at how FreeCAD's QSettings configuration works on Unix systems, where it uses the native format to store settings in `/tmp/.config/FreeCAD/FreeCAD.conf` alongside the user.cfg file, with additional user data like macros stored separately in `/tmp/.local/share/FreeCAD/`.

The key insight is that the modern window and toolbar layout is actually persisted through user parameters in user.cfg rather than the deprecated MainWindowState mechanism, so mounting IDBFS at `/tmp/.config` would capture the essential configuration. However, I need to be careful not to mount IDBFS over the entire `/tmp` directory since it's also used for temporary files and application temp paths — instead I sh  …
Fable
Now let me check how the emscripten runtime exposes addRunDependency, IDBFS, and preRun invocation in the built FreeCAD.js.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && echo \"=== preRun invocation ===\"; grep -no \"preRun\\[i\\](Module)\\|callRuntimeCallbacks\\|preRun.shift()\\|__ATPRERUN__\\|preRun\" FreeCAD.js | head; echo \"=== addRunDepend…
tool result
=== preRun invocation ===
1:preRun
1:preRun
1:preRun
1:preRun
1:preRun
1:preRun
1:preRun
1:callRuntimeCallbacks
1:callRuntimeCallbacks
1:callRuntimeCallbacks
=== addRunDependency exported? ===
1:Module["addRunDependency
=== IDBFS ===
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
1:MEMFS
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I'm noticing that MEMFS showed up in the grep results but IDBFS didn't, so I need to dig into why IDBFS matches were cut off. Let me trace through how preRun gets called with the Module argument, verify that IDBFS is properly registered in the filesystems, and confirm that addRunDependency is exported on the Module object.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && echo \"=== how preRun called ===\"; grep -oE '.{40}preRun\\.(shift|pop|length)[^;]{0,40}' FreeCAD.js | head; echo \"=== callRuntimeCallbacks signature ===\"; grep -oE 'function …
tool result
=== how preRun called ===
=== callRuntimeCallbacks signature ===
=== IDBFS refs count ===
32
=== IDBFS in filesystems ===
filesystems={MEMFS,IDBFS,NODEFS
=== addRunDependency def ===
function addRunDependency(id){runDependencies++;Module["monitorRunDependencies"]?.(runDependencies)
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I'm checking whether IDBFS is properly available in the filesystem registry and confirming that addRunDependency is exported on the Module object. Now I need to trace how preRun callbacks are invoked and what arguments they receive.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/deploy 2>/dev/null; cd /home/magik6k/lcad-wasm/freecad-port/deploy && grep -oE '.{80}callRuntimeCallbacks\\(__ATPRERUN__.{0,20}' FreeCAD.js | head; echo \"=== callRuntimeCallbacks impl ===\"; grep -oE…
tool result
=== callRuntimeCallbacks impl ===
callRuntimeCallbacks=callbacks=>{while(callbacks.length>0){callbacks.shift()(Module)}}
=== preRun consume ===
preRun(){if(Module["preRun"]){if(typeof Module["preRun"]=="function")Module["preRun"]=[Module["preRun"]]
preRun"].length){addOnPreRun(Module["preRun"].shift())}}callRuntimeCallbacks(onPreRuns)}function initRuntime(){runtimeInitiali
preRun()
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
So the preRun callbacks get invoked with Module as the argument, and Module exposes FS, ENV, addRunDependency, and removeRunDependency. I'm checking whether addRunDependency is actually exported on the Module object or if it's just a module-scoped function.

If it's not exported, I can't call it from index.html, so I'd need a different approach — either mounting and syncing the filesystem inside preRun itself, or finding another way to block execution until the async hydration completes. Let me search the generated code to confirm whether addRunDependency and removeRunDependency are actually assigned to Module.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && echo \"=== export assignments ===\"; grep -oE 'Module\\[\"(addRunDependency|removeRunDependency|FS|IDBFS|ENV)\"\\]=' FreeCAD.js | sort -u; echo \"=== EXPORTED_RUNTIME check FS =…
tool result
=== export assignments ===
Module["addRunDependency"]=
Module["ENV"]=
Module["FS"]=
Module["removeRunDependency"]=
=== EXPORTED_RUNTIME check FS ===
Module["FS"]
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I'm checking that all the necessary module exports are available—the dependency management functions, filesystem access, and environment variables—including IDBFS for persistent storage. The key insight is that preRun callbacks execute sequentially, so I need to ensure the IDBFS hydration happens before FreeCAD tries to read its configuration, which means ordering matters in how these callbacks are registered.

Since addRunDependency blocks the main function until all dependencies are resolved, I can add my IDBFS setup as a preRun callback that completes its hydration before main runs, regardless of where it sits in the callback queue. The existing preRun entries that write the startup scrip  …
Fable
Let me verify the FreeCAD Python API for saving parameters and confirm the config write path exists.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -rn \"saveParameter\\|SaveDocument\\|saveConfig\\|\\\"saveParameter\\\"\" src/App/Application.cpp src/App/AppImp.cpp src/App/ApplicationPy.cpp 2>/dev/null | head; echo \"=…
tool result
src/App/ApplicationPy.cpp:58:    {"saveParameter",
src/App/ApplicationPy.cpp:61:     "saveParameter(config='User parameter') -> None\n"
src/App/ApplicationPy.cpp:496:PyObject* ApplicationPy::sSaveDocument(PyObject* /*self*/, PyObject* args)
src/App/ApplicationPy.cpp:636:        param->SaveDocument();
src/App/Application.cpp:694:    doc->signalStartSave.connect(std::bind(&Application::slotStartSaveDocument, this, sp::_1, sp::_2));
src/App/Application.cpp:695:    doc->signalFinishSave.connect(  …[truncated]
Fable
thinking
I've confirmed that `App.saveParameter()` writes to user.cfg, and FreeCAD's initialization creates the /tmp/.config/FreeCAD directory through ExtractUserPath. The IDBFS mount needs to be at /tmp/.config (the parent directory) so that when FreeCAD accesses its config location during startup, the filesystem is properly persisted.

The sequence is clear: preRun mounts IDBFS and hydrates any previously saved config, then during main() FreeCAD initializes and either reads the restored user.cfg or creates a new one. On subsequent loads, the hydration step brings back the saved configuration file. I'm verifying that user.cfg resolves to /tmp/.config/FreeCAD/user.cfg based on how QSettings construct  …
Fable
Let me check the command pump behavior in Gui/Application.cpp to safely reuse it.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/FreeCAD && grep -n \"fc-cmd\\|EMSCRIPTEN\\|singleShot\\|unlink\\|remove(\" src/Gui/Application.cpp | head -20", "description": "Find command pump impl"}
tool result
1171:        QTimer::singleShot(0, [candidates]() {
1750:    d->passive.remove(pcView);
2731:    QTimer::singleShot(0, &mw, SLOT(delayedStartup()));
2733:#ifdef __EMSCRIPTEN__
2749:    QTimer::singleShot(300, []() {
2765:    // snippet to /fc-cmd.py; this repeating timer, firing on the event-loop
2770:        const char* inpath = "/fc-cmd.py";
2771:        const char* runpath = "/fc-cmd-run.py";
2777:        ::remove(runpath);
2779:            ::remove(inpath);
2786:            Base::Console().e  …[truncated]
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/Gui/Application.cpp", "offset": 2760, "limit": 40}
tool result
2760	    });
2761	
2762	    // JS -> Python command pump. A DOM event handler (e.g. the Open/Save UI in
2763	    // index.html) cannot ccall into wasm directly: the main loop is suspended
2764	    // mid-asyncify-unwind and reentering corrupts it. Instead JS writes a Python
2765	    // snippet to /fc-cmd.py; this repeating timer, firing on the event-loop
2766	    // stack, renames it aside (so it runs exactly once even if it throws) and
2767	    // execs it via the same runFile path the startup   …[truncated]
Fable
thinking
The pump consumes commands from /fc-cmd.py within 100ms, so my periodic flush could race with user commands on that shared slot. Since collisions are rare but possible, I'll add a simple guard: only write the flush command if /fc-cmd.py doesn't already exist, checking via filesystem operations where a read error indicates the file is absent.

Now I'm setting up the preRun initialization block in index.html to handle browser persistence. I'm creating a function that mounts IDBFS onto FreeCAD's config and data directories so user preferences, window layouts, macros, and recent files survive across sessions.

The approach blocks FreeCAD's startup until the async hydration from IndexedDB complet  …
Fable
I now have all the facts I need. Let me verify a couple of FS API details and QDir tempPath (to ensure `/tmp` itself isn't the temp path that could collide).
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && echo \"=== FS.stat / FS.syncfs / FS.mount exported ===\"; grep -oE 'FS\\.(stat|syncfs|mount|mkdir)=' FreeCAD.js | sort -u; grep -oE '\"(stat|syncfs|mount|mkdir)\":' FreeCAD.js |…
tool result
=== FS.stat / FS.syncfs / FS.mount exported ===
=== tempPath reads TMPDIR ===
1927:QString QFileSystemEngine::tempPath()
1932:    QString temp = qEnvironmentVariable("TMPDIR");
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && grep -oE 'syncfs:|syncfs\\(|mount:|mount\\(|stat:|analyzePath' FreeCAD.js | sort | uniq -c | head; echo \"=== confirm FS object has these as props ===\"; grep -oE 'syncfs\\(popu…
tool result
      2 analyzePath
     13 mount(
      4 mount:
      4 syncfs(
      1 syncfs:
=== confirm FS object has these as props ===
stat(path
stat(path
stat(path
syncfs(populate,callback)
mount(type,opts,mountpoint)
stat(path
stat(path
stat(path
stat(path
stat(path
=== tempPath fallback ===
QString QFileSystemEngine::tempPath()
{
#ifdef QT_UNIX_TEMP_PATH_OVERRIDE
    return QT_UNIX_TEMP_PATH_OVERRIDE ""_L1;
#else
    QString temp = qEnvironmentVariable("TMPDIR");
#  if defined(Q_OS_DARWIN) && !define  …[truncated]
Fable
thinking
The temporary path resolves to /tmp by default, with AppTempPath pointing directly there rather than into subdirectories like .config or .local/share, so temporary documents aren't persisted and there's no collision risk.

I've confirmed the Emscripten filesystem has all the necessary methods—FS.mount, FS.syncfs, FS.stat, FS.mkdir—and the available filesystems include MEMFS, IDBFS, and NODEFS. Module.addRunDependency and removeRunDependency are exported, preRun callbacks receive the Module argument, and FreeCAD stores its config at /tmp/.config/FreeCAD/ with user.cfg and FreeCAD.conf, while data goes to /tmp/.local/share/FreeCAD/. The App.saveParameter() method writes to user.cfg.

Now I'm r  …
Fable
All facts confirmed. Now let me make the edits to index.html. First, the preRun IDBFS hydrate block.
Fable
⚙ Edit {"replace_all": false, "file_path": "/home/magik6k/lcad-wasm/freecad-port/deploy/index.html", "old_string": " qtContainerElements: [screenEl],\n arguments: [],\n preRun: [(M) => {\n const E = M.ENV;", "new_string": " qtCont…
tool result
The file /home/magik6k/lcad-wasm/freecad-port/deploy/index.html has been updated successfully. (file state is current in your context — no need to Read it back)
Fable
Now add the write-back/persistence helpers and wire them into boot, save, and unload events.
Fable
⚙ Edit {"replace_all": false, "file_path": "/home/magik6k/lcad-wasm/freecad-port/deploy/index.html", "old_string": "createFreeCAD(Module).then((inst) => {\n window.__fc = inst; setStatus('FreeCAD running');\n // Hide the boot overlay a few secon…
tool result
The file /home/magik6k/lcad-wasm/freecad-port/deploy/index.html has been updated successfully. (file state is current in your context — no need to Read it back)
Fable
Now add a persist call after a successful Save so pref changes made during a session get flushed on user action too.
Fable
⚙ Edit {"replace_all": false, "file_path": "/home/magik6k/lcad-wasm/freecad-port/deploy/index.html", "old_string": " setTimeout(() => URL.revokeObjectURL(a.href), 4000);\n setStatus('saved ' + a.download);\n }, 100);", "new_string": "…
tool result
The file /home/magik6k/lcad-wasm/freecad-port/deploy/index.html has been updated successfully. (file state is current in your context — no need to Read it back)
Fable
Let me verify the final file is coherent by viewing the changed regions.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && node --check index.html 2>&1 | head -5 || echo \"note: html not pure js\"; echo \"=== extract inline scripts and syntax-check ===\"; python3 - <<'PY'\nimport re\ns=open('index.h…
tool result
node:internal/modules/esm/get_format:236
  throw new ERR_UNKNOWN_FILE_EXTENSION(ext, filepath);
        ^

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".html" for /home/magik6k/lcad-wasm/freecad-port/deploy/index.html
=== extract inline scripts and syntax-check ===
inline script blocks: 2
block 0: braces 24/24 parens 70/70 len 3774
block 1: braces 36/36 parens 170/170 len 7962
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
I'm checking the syntax of each code block by extracting them to separate files and validating them with Node—the first block contains a Module object literal and the second has function definitions, both of which should be valid standalone.
Fable
⚙ Bash {"command": "cd /tmp/claude-1000/-home-magik6k-lcad-wasm/17f09f89-ce7c-4f49-aa6a-cf0521026805/scratchpad && python3 - <<'PY'\nimport re\ns=open('/home/magik6k/lcad-wasm/freecad-port/deploy/index.html').read()\nscripts=re.findall(r'<script>(…
tool result
== blk0.js ==
OK
== blk1.js ==
OK
zshexit:1: parameter HISTDB_FD does not contain a file descriptor
Fable
thinking
Both code blocks pass syntax validation. Now I'm reviewing the full index.html changes to verify the preRun structure has both callbacks in the right order and that HOME=/tmp is properly set — I notice the IDBFS mount in the first callback references /tmp/.config paths that depend on HOME being set, but HOME is actually configured in the second callback, so there's a potential ordering issue here.

Actually, that's fine because the mount paths are hardcoded to /tmp/.config rather than derived from HOME at mount time, so the order doesn't matter. And /tmp is guaranteed to exist in MEMFS when preRun runs since Emscripten initializes the default filesystem structure before preRun callbacks exec  …
Fable
The edits pass syntax checks. Let me confirm `App.saveParameter()` with no args targets the user.cfg (User parameter) so the probe is accurate.
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/App/ApplicationPy.cpp", "offset": 618, "limit": 24}
tool result
618	    }
619	
620	    PY_TRY
621	    {
622	        ParameterManager* param = App::GetApplication().GetParameterSet(pstr);
623	        if (!param) {
624	            std::stringstream str;
625	            str << "No parameter set found with name: " << pstr;
626	            PyErr_SetString(PyExc_ValueError, str.str().c_str());
627	            return nullptr;
628	        }
629	        if (!param->HasSerializer()) {
630	            std::stringstream str;
631	            str << "Parameter set cannot   …[truncated]
Fable
⚙ Read {"file_path": "/home/magik6k/lcad-wasm/freecad-port/FreeCAD/src/App/ApplicationPy.cpp", "offset": 606, "limit": 13}
tool result
606	    PY_TRY
607	    {
608	        return GetPyObject(GetApplication().GetParameterGroupByPath(pstr));
609	    }
610	    PY_CATCH;
611	}
612	
613	PyObject* ApplicationPy::sSaveParameter(PyObject* /*self*/, PyObject* args)
614	{
615	    const char* pstr = "User parameter";
616	    if (!PyArg_ParseTuple(args, "|s", &pstr)) {
617	        return nullptr;
618	    }
Fable
thinking
I've confirmed the default argument flow—the User parameter gets passed through to SaveDocument, which writes the user.cfg file to the UserParameter path. Now I'm laying out the structured probe steps: first, I'll clear IndexedDB and load the app fresh to establish a clean baseline, then wait for the startup to complete before checking the console.

Next, I'm writing a Python command that sets a test preference value and saves it, then waiting for the pump to process it. After that, I'll trigger the persistence sync either through the persistConfig call or by switching tabs, and verify there are no persistence errors in the logs. Then I reload the page and run another command to read back th  …
Fable
Both facts verified. `App.saveParameter()` defaults to the "User parameter" set, which serializes to `/tmp/.config/FreeCAD/user.cfg`. All edits are syntactically valid and only touch index.html. Let me do a final read of the full edited preRun/boot region to confirm structural integrity.
Fable
⚙ Bash {"command": "cd /home/magik6k/lcad-wasm/freecad-port/deploy && grep -n \"preRun:\\|}, (M) => {\\n\\|addRunDependency\\|removeRunDependency\\|installPersistence\\|persistConfig\\|fcSyncDown\\|FS.mount(IDBFS\\|E.HOME\" index.html", "descripti…
tool result
51:    preRun: [(M) => {
68:        try { FS.mount(IDBFS, {}, m); }
73:      // Application reads it. addRunDependency/removeRunDependency gate run().
74:      M.addRunDependency('fc-idbfs-hydrate');
78:        M.removeRunDependency('fc-idbfs-hydrate');
80:    }, (M) => {
81|      const E = M.ENV;
84:      E.HOME = '/tmp';
126:// IDBFS-backed dirs into IndexedDB. persistConfig(true) does both; the unload
129:function fcSyncDown() {
140:function persistConfig(flushFreeCAD) {
159:    setTimeout(fc  …[truncated]
Fable
All anchors present and structurally correct. The implementation is complete.
Fable
⚙ StructuredOutput {"area": "P0 browser persistence (Tier 0) — IDBFS-backed FreeCAD user config/data survival across reload", "tier": "Tier 0", "needsRebuild": false, "filesAuthored": [], "patchesApplied": [{"file": "/home/magik6k/lcad-wasm/freecad-port/deplo…
tool result
Structured output provided successfully