make[4]: Entering directory '/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/build_dir/target-aarch64_armv8-a_musl-1.1.16/perl/Device-SerialPort-1.04'
aarch64-openwrt-linux-gcc -c  -I. -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -Os -pipe -fno-caller-saves -fno-caller-saves -fno-plt -fhonour-copts -Wno-error=unused-but-set-variable -Wno-error=unused-result -iremap/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/build_dir/target-aarch64_armv8-a_musl-1.1.16/perl/Device-SerialPort-1.04:Device-SerialPort-1.04 -Wformat -Werror=format-security -fstack-protector -D_FORTIFY_SOURCE=1 -Wl,-z,now -Wl,-z,relro -I/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/staging_dir/target-aarch64_armv8-a_musl-1.1.16/usr/include -I/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/staging_dir/target-aarch64_armv8-a_musl-1.1.16/include -I/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/staging_dir/toolchain-aarch64_armv8-a_gcc-5.4.0_musl-1.1.16/usr/include -I/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/staging_dir/toolchain-aarch64_armv8-a_gcc-5.4.0_musl-1.1.16/include/fortify -I/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/staging_dir/toolchain-aarch64_armv8-a_gcc-5.4.0_musl-1.1.16/include -O2   -DVERSION=\"1.04\" -DXS_VERSION=\"1.04\" -fPIC "-I/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/staging_dir/target-aarch64_armv8-a_musl-1.1.16/usr/lib/perl5/5.22/CORE/"   SerialPort.c
SerialPort.xs:1:20: fatal error: EXTERN.h: No such file or directory
compilation terminated.
Makefile:340: recipe for target 'SerialPort.o' failed
make[4]: *** [SerialPort.o] Error 1
make[4]: Leaving directory '/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/build_dir/target-aarch64_armv8-a_musl-1.1.16/perl/Device-SerialPort-1.04'
Makefile:53: recipe for target '/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/build_dir/target-aarch64_armv8-a_musl-1.1.16/perl/Device-SerialPort-1.04/.built' failed
make[3]: *** [/build/lede-17.01/slaves/phase2/aarch64_armv8-a/build/sdk/build_dir/target-aarch64_armv8-a_musl-1.1.16/perl/Device-SerialPort-1.04/.built] Error 2