Steps to reproduce:

• on a system without mage installed, clone a Go 1.11 module project that uses mage, e.g. https://github.com/dmolesUC3/cos

• attempt to follow the installation instructions:

  go get -u -d github.com/magefile/mage
  cd $GOPATH/src/github.com/magefile/mage    # ← fails
  go run bootstrap.go
  

Expected:

• mage is installed

Actual:

• cd fails with:

  -bash: cd: /Users/david/Projects/Go/src/github.com/magefile/mage: No such file or directory
  

• running find $GOPATH -type d -name mage shows only:

  /Users/david/Projects/Go/pkg/mod/cache/download/github.com/magefile/mage
  /Users/david/Projects/Go/pkg/mod/github.com/magefile/mage@v1.8.0/mage
  

Workaround:

• change to a directory outside the project, e.g. $HOME, and rerun the installation instructions from there

Proposed change:

• better installation instructions for users whose first exposure to mage is in the context of trying to build someone else's magefile-ized module project.