myitcv.io/go

myitcv.io/go is a wrapper around the go tool that automatically sets the GOPATH env variable based on the process' current directory (which we refer to as $PWD for brevity). See the Goal section below for motivation.

The GOPATH passed to the go tool is calculated as follows:

1. The existence of a ._gopath file in a directory d1 sets GOPATH to d1; this is evaluated for each directory d1 on the path from $PWD towards /. If no such d1 exists, set GOPATH to the myitcv.io/go process' environment variable GOPATH (if set), else $HOME/go
2. The existence of a _vendor directory in a directory d2 causes d2/_vendor to be prepended to GOPATH. This is evaluated for each directory d2 on the path from d1 (or / if d1 did not exist) towards $PWD.

The algorithm is relatively simple; myitcv.io/go/updateenv's init should be relatively understandable therefore.

Usage

myitcv.io/go is designed to be used in place of the go tool. Indeed it is implemented under the assumption that myitcv.io/go resolves before the go tool in your PATH.

Therefore, assuming the go tool is already on your PATH, do something equivalent to the following

go get -u myitcv.io/go
mkdir -p "$HOME/bin/myitcv_io_go"
go build -o "$HOME/bin/myitcv_io_go/go" myitcv.io/go

and then ensure $HOME/bin/myitcv_io_go is at the beginning of your PATH:

# in .bashrc or equivalent
export PATH="$HOME/bin/myitcv_io_go:$PATH"

# ...

Goal of this tool

The goal behind this tool is to explore how a true auto-GOPATH implementation might work within Go proper. But there is an obvious flaw to the approach of "wrapping" the go tool: any program other than the go tool that depends on a package that itself uses the value of GOPATH will no longer function correctly. Hence myitcv.io/go imports myitcv.io/go/updateenv for its side effect where the process' GOPATH environment variable is updated. Other programs should import this package for its side effects and be recompiled to experiment with this change in behaviour.