chore: enhance build_musl.sh script for improved output handling and error checking

- Updated the script to use 'set -euo pipefail' for better error handling.
- Added dynamic output directory detection from config.mak.
- Implemented checks to ensure the output directory exists before proceeding with installation.
- Improved the copying of output files to /opt/musl with error handling.

Author: scc-tw

common/build/deplib/build_musl.sh

@@ -1,10 +1,26 @@
 #!/bin/bash
 
-set -e
+set -euo pipefail
 git clone --depth 1 https://github.com/25077667/musl-cross-make.git
 
 cp ./config.mak musl-cross-make/config.mak
 
-cd musl-cross-make && make -j $(nproc) install && cp -r output /opt/musl
+OUTPUT_DIR="$(awk -F= '/^[[:space:]]*OUTPUT[[:space:]]*=/{print $2}' ./config.mak | xargs || true)"
+if [ -z "${OUTPUT_DIR}" ]; then
+  OUTPUT_DIR="output"
+fi
+
+cd musl-cross-make
+make -j "$(nproc)" install
+
+OUTPUT_PATH="${OUTPUT_DIR}"
+
+if [ ! -d "${OUTPUT_PATH}" ]; then
+  echo "musl-cross-make output directory not found: ${OUTPUT_PATH}" >&2
+  exit 1
+fi
+
+mkdir -p /opt/musl
+cp -a "${OUTPUT_PATH}/." /opt/musl/
 find /opt/musl -iname "*.la" -type f -exec sed -i "s/libdir='/libdir='\/opt\/musl/g" "{}" \;
 find /opt/musl -iname "*.la" -type f -exec sed -i "s/installed=yes/installed=no/g" "{}" \;