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 get 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 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. You will also need to update the go directive in your go.mod file to refer to go 1.18 to use generics.

Build and install the latest unstable version of gopls following the instruction. Remember to use gotip instead of go.

The gopls build with this instruction 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 .