First, build a bootstrap tool called dist:
https://github.com/golang/go/blob/release-branch.go1.5/src/make.bash#L121
Be aware of $GOROOT_BOOTSTRAP, In my currently env i build through:
GOROOT_BOOTSTRAP=/home/sunan/go/src/go1.4/ ./make.bash
That's where my go1.4 placed
try to add exit at line 122
And add exit @line 146
Then, We need to execute is dist by ourself:
GOROOT_BOOTSTRAP=/home/sunan/go/src/go1.4/ ./cmd/dist/dist bootstrap -a -v
It will Building Go toolchain using /home/sunan/go/src/go1.4 for us