PATH="$nix:$PATH"
export PATH
NEED_PROG([NIX_STORE], [nix-store])
AC_MSG_CHECKING([whether $NIX_STORE is recent enough])
if "$NIX_STORE" --timeout 123 -q > /dev/null 2>&1
then
    AC_MSG_RESULT([yes])
else
    AC_MSG_RESULT([no])
    AC_MSG_ERROR([`$NIX_STORE' doesn't support `--timeout'; please use a newer version.])
fi