An alternative to building a Go 1.4.3 bootstrap environment, is to build a Go 1.7 bootstrap environment for Plan 9 in a mainstream environment like Linux or Mac OS X, then use it to build Go 1.7 on Plan 9. General outline is to:
* follow the instructions on how to clone and build Go 1.7 on, say, Linux.
* once Go is built and installed, build a Plan 9 bootstrap
cd $GOROOT/src
GOOS=plan9 GOARCH=386 ./boostrap.bash
this produces the bootstrap hierarchy in ../../go-plan9-386-bootstrap. copy the hierarchy over to Plan 9 and set GOROOT_BOOTSTRAP to that location, then build Go 1.7 on Plan 9.
The general explanation of bootstrapping Go is here:
FYI, when i need to 'git clone' something on Plan 9, I mount the fs from Linux (p9p) and do the git stuff there.