On my old chumby boards, though, which are hamstrung for memory, I do cross-compile (in Windows!) and then rsync the resulting binary over, which is a much quicker turn around than compiling on the device and yes, the cross-compile system in Go is absolutely delightful compared to C/C++ toolchain hell.
I could just ssh into the Pi and build there, but it would actually be more of a hassle than cross compiling; an impressive feat.
Basically cross-compiling in Go is as easy as setting a few environmental variables to describe which OS/arch you want to compile for, though you have to do some from-source building of the Go toolchain in order to get the different compilers for different arches.
But you should be building from source if targeting ARM anyway because the current full Go binary release has much worse ARM support than the current +tip branch of Go in Go's mercurial repo.
While I'm curious, this sounds like a bout of a bummer.
I think I'll wait a little bit longer ;)
EDIT: On Raspbian, haven't tried with FreeBSD.