Correct INSTALL_PREFIX for arm64 target

scripts/setup-helper-functions.sh

@@ -15,6 +15,9 @@
 
 # github_checkout $REPO $VERSION $GIT_CLONE_PARAMS clones or re-uses an existing clone of the
 # specified repo, checking out the requested version.
+
+OS=$(uname)
+
 function github_checkout {
   local REPO=$1
   shift
@@ -55,8 +58,6 @@ function github_checkout {
 function get_cxx_flags {
   local CPU_ARCH=$1
 
-  local OS
-  OS=$(uname)
   local MACHINE
   MACHINE=$(uname -m)
   ADDITIONAL_FLAGS=""
@@ -129,6 +130,11 @@ function cmake_install {
   CPU_TARGET="${CPU_TARGET:-unknown}"
   COMPILER_FLAGS=$(get_cxx_flags $CPU_TARGET)
 
+  if [[ "$OS" == "Darwin" && "${CPU_TARGET}" == "arm64" ]]; then
+   INSTALL_PREFIX="${INSTALL_PREFIX:-/opt/homebrew}"
+  fi
+
+
   # CMAKE_POSITION_INDEPENDENT_CODE is required so that Velox can be built into dynamic libraries \
   cmake -Wno-dev -B"${BINARY_DIR}" \
     -GNinja \