Closes#2112
The host `cargo zigbuild` for `*-unknown-linux-musl` opens ~333 `.rlib`
files at once during the static link, exceeding macOS's default soft
limit of 256 and failing with `ProcessFdQuotaExceeded`. This blocked the
docker/podman `mise run gateway` paths for macOS contributors; only the
VM driver path guarded against it.
Extract the VM path's `ensure_build_nofile_limit` guard into a shared
`tasks/scripts/build-env.sh` and call it from the host-staging chokepoint
(`stage-prebuilt-binaries.sh`), fixing docker, podman, and all
docker:*/multiarch host cross-compiles at once. De-duplicate the VM
script to source the shared helper. The guard is a no-op on Linux and
when cargo-zigbuild is absent, so CI and Linux dev are unaffected. The
limit is read from `OPENSHELL_BUILD_NOFILE_LIMIT` (default 8192),
honoring the legacy `OPENSHELL_VM_BUILD_NOFILE_LIMIT` for back-compat.
Also correct the stale comment in gateway-docker.sh (the cross-compile
runs on the host, not inside Linux containers) and document the guard in
architecture/build.md. Adds tasks/scripts/test-build-env.sh, wired into
`mise run test` via `test:build-env`.
Signed-off-by: Jim Meyer <jim@meyer4hire.com>
