#!/bin/shset -eu MUPDF_OUTPUT_DIR="$1"u="git://git.ghostscript.com/mupdf"#u="https://github.com/ArtifexSoftware/mupdf"MUPDF_URL="${2-$u}"MUPDF_DESIRED_VERSION="f6ddaf30da1defe3be961f1172b83554bc6f6b48" if [ ! -d ${MUPDF_OUTPUT_DIR} ]; then    echo "mupdf does not exist, fetching it from ${MUPDF_URL}"    git clone ${cloneargs-} ${MUPDF_URL} --recursive ${MUPDF_OUTPUT_DIR}fi cd ${MUPDF_OUTPUT_DIR}git remote updateMUPDF_VERSION=$(git rev-parse HEAD) test "${MUPDF_VERSION}" = "${MUPDF_DESIRED_VERSION}" || {    printf "mupdf current version is ${MUPDF_VERSION} "    echo "switching to ${MUPDF_DESIRED_VERSION}"    git reset --hard ${MUPDF_DESIRED_VERSION}    git submodule update --init --recursive}