错误:/linux_amd64/bytes.a:不是软件包文件

I am trying to install 'vet' tool using go get, and I am getting this error:

root@ubuntu:~/docker# go get code.google.com/p/go.tools/cmd/vet
# code.google.com/p/go.tools/cmd/vet
../go/src/code.google.com/p/go.tools/cmd/vet/asmdecl.go:10: import /root/go/pkg/linux_amd64/bytes.a: not a package file

I tried to find the solution on internet, couldn't find anything helpful. Could you guys please help me figure out what could be causing this? TIA.

Okay, so the problem was I was using go 1.2.1, I upgraded it to 1.4.2 and everything is working fine now. Thanks, @Ainar-G for pointing it out.