clean up build script a bit

Quda/build-quda.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+# shellcheck disable=SC1090,SC1091
+
+BUILD_FLAGS="-O3 -std=c++17"
+QUDA_FLAGS="-DQUDA_MPI=ON -DQUDA_PRECISION=14 -DQUDA_RECONSTRUCT=4 -DQUDA_GPU_ARCH=sm_80"
+
+set -euo pipefail
+
+if (( $# != 1 )); then
+    echo "usage: $(basename "$0") <environment directory>" 1>&2
+    exit 1
+fi
+env_dir=$1
+
+call_dir=$(pwd -P)
+mkdir -p ${env_dir}
+cd "${env_dir}"
+env_dir=$(pwd -P)
+cd "${call_dir}"
+
+build_dir="${env_dir}/build/quda"
+if [ -d "${build_dir}" ]; then
+    echo "error: directory '${build_dir}' exists"
+    exit 1
+fi
+mkdir -p "${build_dir}"
+
+git clone https://github.com/lattice/quda.git "${build_dir}"
+cd "${build_dir}"
+
+mkdir build; cd build
+cmake .. $QUDA_FLAGS -DCMAKE_INSTALL_PREFIX=${env_dir}/prefix/quda
+make -j128
+make install
+
+cd "${call_dir}"