NEED_PROG([NIX_STORE], [nix-store])

NEED_PROG([NIX_STORE_PROGRAM], [nix-store])

AC_MSG_CHECKING([whether $NIX_STORE is recent enough])
if "$NIX_STORE" --timeout 123 -q > /dev/null 2>&1

AC_MSG_CHECKING([whether $NIX_STORE_PROGRAM is recent enough])
if "$NIX_STORE_PROGRAM" --timeout 123 -q > /dev/null 2>&1

    AC_MSG_ERROR([`$NIX_STORE' doesn't support `--timeout'; please use a newer version.])

    AC_MSG_ERROR([`$NIX_STORE_PROGRAM' doesn't support `--timeout'; please use a newer version.])