Zephyr: Avoid host library path when running SDK tools

The Zephyr CI image sets LD_LIBRARY_PATH globally to include host
system library directories. When Zephyr SDK host tools such as dtc
are launched, this can make the SDK dynamic loader resolve libraries
from the host instead of the SDK hosttools sysroot.

Sanitize LD_LIBRARY_PATH for Zephyr west build commands so SDK host
tools use their intended runtime libraries, while preserving
sample-specific entries such as FVP paths.

Signed-off-by: Zingo Andersen <Zingo.Andersen@arm.com>
Change-Id: I036dd0ae732bbfe20c8e6c41831692a3bb7c6f60

Author: zingo

.ci/scripts/test_zephyr.sh

@@ -99,6 +99,48 @@ cd "${EXECUTORCH_PROJ_ROOT}"
 . .ci/scripts/utils.sh
 . .ci/scripts/zephyr-utils.sh
 
+sanitize_zephyr_ld_library_path() {
+  local -a ld_entries
+  local cuda_lib entry output
+
+  cuda_lib="${CUDA_HOME:+${CUDA_HOME}/lib64}"
+  output=""
+  IFS=':' read -r -a ld_entries <<< "${LD_LIBRARY_PATH:-}"
+  for entry in "${ld_entries[@]}"; do
+    if [[ -z "${entry}" || "${entry}" == "/usr/lib/x86_64-linux-gnu" ]]; then
+      continue
+    fi
+    if [[ -n "${cuda_lib}" && "${entry}" == "${cuda_lib}" ]]; then
+      continue
+    fi
+
+    if [[ -z "${output}" ]]; then
+      output="${entry}"
+    else
+      output="${output}:${entry}"
+    fi
+  done
+
+  printf '%s\n' "${output}"
+}
+
+west() {
+  local sanitized_ld_library_path
+
+  if [[ "${1:-}" != "build" ]]; then
+    command west "$@"
+    return
+  fi
+
+  sanitized_ld_library_path="$(sanitize_zephyr_ld_library_path)"
+  echo "Using sanitized LD_LIBRARY_PATH for west build: ${sanitized_ld_library_path:-<unset>}"
+  if [[ -n "${sanitized_ld_library_path}" ]]; then
+    LD_LIBRARY_PATH="${sanitized_ld_library_path}" command west "$@"
+  else
+    env -u LD_LIBRARY_PATH west "$@"
+  fi
+}
+
 run_target_test_blocks_from_readme() {
   local readme_path="$1"
   local target="$2"
@@ -201,7 +243,7 @@ print_tool_details() {
 print_path_details() {
   local label="$1"
   local path="$2"
-  local interpreter
+  local interpreter sanitized_ld_library_path
 
   echo "${label}: ${path}"
   if [[ -e "${path}" ]]; then
@@ -214,6 +256,13 @@ print_path_details() {
     fi
     if [[ -x "${path}" ]]; then
       "${path}" --version || true
+      sanitized_ld_library_path="$(sanitize_zephyr_ld_library_path)"
+      echo "${label} --version with sanitized LD_LIBRARY_PATH: ${sanitized_ld_library_path:-<unset>}"
+      if [[ -n "${sanitized_ld_library_path}" ]]; then
+        LD_LIBRARY_PATH="${sanitized_ld_library_path}" "${path}" --version || true
+      else
+        env -u LD_LIBRARY_PATH "${path}" --version || true
+      fi
     fi
   else
     echo "${label}: missing"
@@ -234,7 +283,7 @@ print_zephyr_diagnostics() {
   echo "ZEPHYR_SDK_INSTALL_DIR: ${ZEPHYR_SDK_INSTALL_DIR:-<unset>}"
   echo "ZEPHYR_TOOLCHAIN_VARIANT: ${ZEPHYR_TOOLCHAIN_VARIANT:-<unset>}"
   echo "ZEPHYR_SDK_RELEASE_PROXY_CACHE_DIR: ${ZEPHYR_SDK_RELEASE_PROXY_CACHE_DIR:-<unset>}"
-  echo "EXECUTORCH_ZEPHYR_DTC: ${EXECUTORCH_ZEPHYR_DTC:-<unset>}"
+  echo "Sanitized LD_LIBRARY_PATH: $(sanitize_zephyr_ld_library_path || true)"
 
   sdk_version="$(python3 "${EXECUTORCH_PROJ_ROOT}/.ci/docker/common/zephyr_sdk_release_proxy.py" --print-version)"
   echo "Zephyr SDK version: ${sdk_version}"