At the end of http://www.gnu.org/software/gmp/manual/html_node/Autoconf.html some closing parentheses are missing. It should read: AC_CHECK_LIB(mpfr, mpfr_add, , [AC_MSG_ERROR( [Need MPFR either from GNU MP 4 or separate MPFR package. See http://www.mpfr.org or http://swox.com/gmp]) ]) "])" are missing. Ralf