os: build bootable images

hack/build/cargo.sh

@@ -4,5 +4,10 @@ set -e
 TOOLS_DIR="$(dirname "${0}")"
 RUST_TARGET="$("${TOOLS_DIR}/target.sh")"
 
+if [ "${RUST_LIBC}" = "musl" ] && [ -f "/etc/alpine-release" ]
+then
+  export RUSTFLAGS="-Ctarget-feature=-crt-static"
+fi
+
 export CARGO_BUILD_TARGET="${RUST_TARGET}"
 exec cargo "${@}"