How to point Go module dependency in go.mod to a latest commit in a repo?

Question

Starting with v1.11 Go added support for modules. Commands

go mod init <package name>
go build

would generate go.mod and go.sum files that contain all found versions for the package dependencies.

If a module does not have any releases, the latest commit of that module is used. If a module does have releases, the latest one is picked as a dependency.

However sometimes I would need functionality that is not in a published release yet, but from a commit made after that release. How do I set go.mod to point not to a release of a module, but to a specific commit in the module's repository?

It looks like I can do it by hand in go.mod with

module /my/module

require (
...
github.com/someone/some_module v0.0.0-20181121201909-af044c0995fe
...
)

where v0.0.0 does not correspond to the last published release tag, 20181121201909 would be a commit timestamp and af044c0995fe would be the commit hash? Should such information to be found and entered by hand, or there is a better way?

Answer 1

Just 'go get' at the commit hash you want:

go get github.com/someone/some_module@af044c0995fe

'go get' will correctly update the dependency files (go.mod, go.sum).

More information: https://github.com/golang/go/wiki/Modules#how-to-upgrade-and-downgrade-dependencies