Despite my earlier voiced contempt for MacPorts, I present you build_macports64, a small script which bootstraps a 64-bit MacPorts environment from their SVN repository. No manual intervention is required.
Dependencies: 32-bit MacPorts installed (you want to keep it anyway for the moment), and a configured sudo. By default, it installs to /opt/local64/.
I have the following packages build and installed (here, universal means x86_64):
% port installed The following ports are currently installed: apr @1.3.3_1+universal (active) apr-util @1.3.4_1+universal (active) bzip2 @1.0.5_2+universal (active) curl @7.19.5_0+universal (active) db45 @4.5.20_4+universal (active) db46 @4.6.21_5+universal (active) expat @2.0.1_0+universal (active) gettext @0.17_4+universal (active) gmake @3.81_0+universal (active) gperf @3.0.4_0+universal (active) libiconv @1.12_2+universal (active) ncurses @5.7_0+universal (active) ncursesw @5.7_0+universal (active) openssl @0.9.8k_0+universal (active) pkgconfig @0.23_1+universal (active) popt @1.15_0+universal (active) readline @6.0.000_1+universal (active) sqlite3 @184.108.40.206_0+universal (active) tcl @8.5.6_0+threads+universal (active) zlib @1.2.3_2+universal (active)
Sadly, at the moment there are some crucial packages which do not
build as x86_64 even if requested (perl, boost). For others,
the build just breaks, e.g., because
not passed properly. But that was to be expected, I guess. With
more people using it and reporting/fixing bugs, the situation is
likely to improve over time.