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

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?

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

In addition the answer from Everton on using go get github.com/someone/some_module@af044c0995fe to get a specific commit, you can also use branch names such as:

• go get github.com/someone/some_module@master
• go get github.com/someone/some_module@dev_branch

Those examples get the latest commit on the corresponding branch.

It will still be recorded as a pseudo-version in your go.mod file, such as v0.0.0-20171006230638-a6e239ea1c69. (This helps provide a simple total ordering across all versions based on standard semver ordering).

If you want to temporarily substitute a dependency to a local directory (for example if you work on 2 modules sumultaneously) you can add replace statement at the end of go.mod file:

module example.com/mypkg

go 1.15

require (
  gitlab.com/someone/a_package v0.14.2
)

replace gitlab.com/someone/a_package => ../my_forks/a_package

I have been banging my head for some time that how it works for everyone and I am not able to run it. For me, I had to commit to master branch then only I was able to get it.

For go get to work with specific branch, commit id or tag, you need to enable a flag for go module by running below command

> go env -w GO111MODULE=on

after this we will be able to do

go get repo@branchname
go get repo@tag
go get repo@commithash

Also if you put the word latest in place of the tag in the go.mod file it will get changed to the latest tag the modules.

For example:

module /my/module

require (
...
github.com/someone/some_module latest
...
)

will become

module /my/module

require (
...
github.com/someone/some_module v2.0.39
...
)

after running go mod tidy

• Download source from branch
  go get your-repo@branch-name read output with go module version to be added to require or replace:
  go: downloading github.com/your-repo v1.2.3-0.20210609123456-123123123
• Later this version can be found as output string of the following command
  go list -m -json your-repo@branch-name | jq '.|"\(.Path) \(.Version)"'
• If jq is not installed on your PC - manually combine Path and Version values of result from:
  go list -m -json your-repo@branch-name
  separated by space:
  your-repository v1.2.3-0.20210609123456-123123123