Advanced topics

This documentation is for advanced gopls users, who may want to test unreleased versions or try out special features.

Installing unreleased versions

To get a specific version of gopls (for example, to test a prerelease version), run:

GO111MODULE=on go install golang.org/x/tools/gopls@vX.Y.Z

Where vX.Y.Z is the desired version.

Unstable versions

To update gopls to the latest unstable version, use:

# Create an empty go.mod file, only for tracking requirements.
cd $(mktemp -d)
go mod init gopls-unstable

# Use 'go get' to add requirements and to ensure they work together.
go get golang.org/x/tools/gopls@master golang.org/x/tools@master

# For go1.17 or older, the above `go get` command will build and
# install `gopls`. For go1.18+ or tip, run the following command to install
# using selected versions in go.mod.
go install golang.org/x/tools/gopls

Working on the Go source distribution

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.

Working with generic code

Gopls has beta support for editing generic Go code, 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 generics. The easiest way to do this is by installing Go 1.18 Beta 1 as described at Tutorial: Getting started with generics#prerequisites, and then using this Go version to build gopls:

$ go1.18beta1 install golang.org/x/tools/gopls@latest

When using the Go 1.18, it is strongly recommended that you install the latest version of gopls, or the latest unstable version as described above.

The gopls built with these instructions understands generic code. To actually run the generic code you develop, you must also use the beta version of the Go compiler. For example:

$ go1.18beta1 run .