Harden LinuxCNC wasm and native probe workflows

test-linuxcnc-bridge-native.sh

@@ -5,8 +5,14 @@ cd "$(dirname "$0")"
 
 linuxcnc_root=${LINUXCNC_ROOT:-../linuxcnc}
 cxx=${CXX:-g++}
-build_dir=${TMPDIR:-/tmp}/cnc_sim_native
-mkdir -p "$build_dir"
+build_dir=$(mktemp -d "${TMPDIR:-/tmp}/cnc_sim_native.XXXXXX")
+
+if [[ ! -d "$linuxcnc_root" ]]; then
+    echo "missing LinuxCNC root: $linuxcnc_root" >&2
+    exit 1
+fi
+
+trap 'rm -rf "$build_dir"' EXIT
 
 "$cxx" -std=c++17 \
     -I core/include \