Configuring fails on missing mpc.h on Mac OS 10.5.8

[Rouson, Damian]

I just did an svn update and also tried a fresh checkout, but both fail to
configure because configure can't find mpc.h.  Is this a new requirement? I
never needed it before.  I'm on Mac OS 10.5.8.  My configure line and the
tail of the output are below.  I installed mpc via macports, but it didn't
seem to install mpc.h.

Configure line: 

/Users/rouson/fortran-dev/configure --program-suffix=-4.5 \
--enable-checking=release --prefix=/usr/local/gfortran \
--enable-languages=c,fortran --enable-version-specific-runtime-libs \
--build=x86_64-apple-darwin9 --host=x86_64-apple-darwin9 \
--target=x86_64-apple-darwin9 --disable-bootstrap --disable-multilib \
--with-gmp=/opt/local --with-mpfr=/opt/local --with-mpc=/opt/local \
--with-libiconv-prefix=/opt/local

Output tail:

checking for correct version of gmp.h... yes
checking for correct version of mpfr.h... yes
checking for the correct version of mpc.h... no
configure: error: Building GCC requires GMP 4.2+, MPFR 2.3.2+ and MPC
0.8.0+.
Try the --with-gmp, --with-mpfr and/or --with-mpc options to specify
their locations.  Source code for these libraries can be found at
their respective hosting sites as well as at
ftp://gcc.gnu.org/pub/gcc/infrastructure/.  See also
http://gcc.gnu.org/install/prerequisites.html for additional info.  If
you obtained GMP, MPFR and/or MPC from a vendor distribution package,
make sure that you have installed both the libraries and the header
files.  They may be located in separate packages.

Any advice?

Damian