Environment variables & build knobs

Version selection

These control which dist/<ver> directory is “active” for helper scripts:

They are consumed by dist_version.py and check/dist_paths.mjs.

EMSDK: path to your emsdk directory (must contain emsdk_env.sh). Required by the Emscripten CMake build.
MJWF_BASH: override the bash executable used by forge_cli.py for bash -lc ... invocations (useful on Windows).

MJWF_GIT_CLEAN_IGNORED=1: enable git clean -fdx when refreshing external/mujoco (default is git clean -fd to avoid OneDrive permission issues).

MJWF_BUILD_ROOT: root directory for intermediate build trees (defaults to <repo>/build).

MJWF_EXPORTS_LIST: override the export list path passed to the link step (defaults to dist/<ver>/abi/exports.lst).

MJWF_DIST_VARIANT: optional dist subdirectory selector consumed by check/dist_paths.mjs (e.g. pthreads).

app/CMakeLists.txt defines a CMake cache variable MJWF_PROFILE with the following values:

Profiles mainly change optimization/debug flags, filesystem settings, and related link options.

These variables control pthread worker pool sizing and stability knobs for the --pthreads variant:

MJWF_PTHREAD_POOL_SIZE: integer >=1 (default: 4). Sets Emscripten -sPTHREAD_POOL_SIZE=<n> to prewarm a fixed WebWorker pool.
MJWF_PTHREADS_COMPILER_MAX_THREADS: cap MuJoCo XML compiler threads:
- unset / empty: use default (for MuJoCo 3.5.0 pthreads, defaults to MJWF_PTHREAD_POOL_SIZE).
- 0: disable clamp (use upstream hardware_concurrency()/2 behavior).
- N>=1: clamp to <=N.

gates.mjs checks wasm/js size and init time.