This documentation is for advanced gopls users, who may want to test unreleased versions or try out special features.
To get a specific version of gopls (for example, to test a prerelease version), run:
GO111MODULE=on go get golang.org/x/tools/gopls@vX.Y.Z
Where vX.Y.Z is the desired version.
To update gopls to the latest unstable version, use:
GO111MODULE=on go get golang.org/x/tools/gopls@master golang.org/x/tools@master
If you are working on the Go project itself, the go command that gopls invokes will have to correspond to the version of the source you are working on. That is, if you have checked out the Go project to $HOME/go, your go command should be the $HOME/go/bin/go executable that you built with make.bash or equivalent.
You can achieve this by adding the right version of go to your PATH (export PATH=$HOME/go/bin:$PATH on Unix systems) or by configuring your editor.
Gopls has experimental support for generic Go, as defined by the type parameters proposal (golang/go#43651) and type set addendum (golang/go#45346).
To enable this support, you need to build gopls with a version of Go that supports type parameters, currently just tip. This can be done by checking out the master branch in the Go repository, or by using golang.org/dl/gotip:
$ go get golang.org/dl/gotip $ gotip download
For building gopls with type parameter support, it is recommended that you build gopls at tip. External APIs are under active development on the Go master branch, so building gopls at tip minimizes the chances of a build failure (though it is still possible). To get enhanced gopls features for generic code, build gopls with the typeparams build constraint (though this increases your chances of a build failure).
$ GO111MODULE=on gotip get -tags=typeparams golang.org/x/tools/gopls@master golang.org/x/tools@master
This will build a version of gopls that understands generic code. To actually run the generic code you develop, you must also use the tip version of the Go compiler. For example:
$ gotip run .