Change:
fi fi <del> if [[ -n "${1-}" ]]; then cover_report_dir="" if [[ -n "${KUBE_COVER}" ]]; then cover_report_dir="/tmp/k8s_coverage/$(kube::util::sortable_date)" kube::log::status "Saving coverage output in '${cover_report_dir}'" fi for arg; do trap 'exit 1' SIGINT pkg=${KUBE_GO_PACKAGE}/${arg} cover_params=() if [[ -n "${KUBE_COVER}" ]]; then mkdir -p "${cover_report_dir}/${arg}" cover_params=(${KUBE_COVER} -coverprofile="${cover_report_dir}/${arg}/coverage.out") fi </del> <ins> # If we're not collecting coverage, run all requested tests with one 'go test' # command, which is much faster. if [[ ! ${KUBE_COVER} =~ ^[yY]$ ]]; then kube::log::status "Running unit tests without code coverage" go test "${goflags[@]:+${goflags[@]}}"  ${KUBE_RACE} ${KUBE_TIMEOUT} "${@+${@/#/${KUBE_GO_PACKAGE}/}}" exit 0 fi # Create coverage report directories. cover_report_dir="/tmp/k8s_coverage/$(kube::util::sortable_date)" cover_profile="coverage.out"  # Name for each individual coverage profile kube::log::status "Saving coverage output in '${cover_report_dir}'" mkdir -p "${@+${@/#/${cover_report_dir}/}}" # Run all specified tests, collecting coverage results. Go currently doesn't # support collecting coverage across multiple packages at once, so we must issue # separate 'go test' commands for each package and then combine at the end. # To speed things up considerably, we can at least use xargs -P to run multiple # 'go test' commands at once. printf "%sn" "${@}" | xargs -I{} -n1 -P${KUBE_COVERPROCS}  </ins> go test "${goflags[@]:+${goflags[@]}}"  ${KUBE_RACE}  ${KUBE_TIMEOUT}  <ins> -cover -covermode="${KUBE_COVERMODE}"  -coverprofile="${cover_report_dir}/{}/${cover_profile}"  </ins> "${cover_params[@]+${cover_params[@]}}"  <del> "${pkg}" done exit 0 </del> <ins> "${KUBE_GO_PACKAGE}/{}" combined_cover_profile="${cover_report_dir}/combined-coverage.out" { # The combined coverage profile needs to start with a line indicating which # coverage mode was used (set, count, or atomic). This line is included in # each of the coverage profiles generated when running 'go test -cover', but # we strip these lines out when combining so that there's only one. echo "mode: ${KUBE_COVERMODE}" # Include all coverage reach data in the combined profile, but exclude the # 'mode' lines, as there should be only one. find "${cover_report_dir}" -name "${cover_profile}" | xargs -r grep -h -v "^mode:" || true } >"${combined_cover_profile}" coverage_html_file="${cover_report_dir}/combined-coverage.html" go tool cover -html="${combined_cover_profile}" -o="${coverage_html_file}" kube::log::status "Combined coverage report: ${coverage_html_file}" if [[ -x "${KUBE_GOVERALLS_BIN}" ]]; then ${KUBE_GOVERALLS_BIN} -coverprofile="${combined_cover_profile}" || true </ins> fi <del> kube::test::find_pkgs | xargs go test "${goflags[@]:+${goflags[@]}}"  ${KUBE_RACE}  ${KUBE_TIMEOUT}  ${KUBE_COVER} </del>

Discussion:
Our test- script invokes 'go test' serially for each pkg - currently taking 2 minutes on my laptop. Running a single 'go test' for all pkgs cuts the time down to 45 seconds. Even running with -race is only 1:15. As far as I can tell, the only time we HAVE to run serially is when coverage is on. Does anyone have time to fix this?
I'd created on Friday to fix this, though it's not yet been reviewed.
I cobbled together but I'll review yours since it is probably better :) , Jeff Grafton wrote: