My answer is in reference to the setting-up of go-lang on Ubuntu linux/amd64.I have faced the same trouble of setting the path of environment variables (GOPATH and GOBIN), losing it on terminal exit and rebuilding it using the source every time.The mistake was to put the path (GOPATH and GOBIN) in ~/.bash_profile folder. After wasting a few good hours, I found that the solution was to put GOPATH and GOBIN in ~/.bash_rc file in the manner:
export GOPATH=$HOME/go
export GOBIN=$GOPATH/bin
export PATH=$PATH:$GOPATH:$GOBIN
and doing so, the go installation worked fine and there were no path losses.
EDIT 1:
The reason with which this issue can be related is that settings for non-login shells like your ubuntu terminal or gnome-terminal where we run the go code are taken from ~./bash_rc file and the settings for login shells are taken from ~/.bash_profile file, and from ~/.profile file if ~/.bash_profile file is unreachable.
