cmd/go: compile environment variable into binary during `go get'

[VojtechVitek]

Hi gophers,

there are lots of "go get"-able CLI programs out there on Github but most of them don't have a built-in version flag/sub-command, just because it's almost impossible to compile an environment variable into a binary during the go get -u <pkg/cmd> invocation.

I wonder, are there any plans on making go get more robust and let it

1. Invoke go:generate automatically on go get?
2. Or set an environment variable during go get, an equivalent of explicit -ldflags "-X main.Version=$(git describe --tags)"?
3. Any other ideas?

I know this all can be "automated" in Makefile, but the question is if we can ever expect the go get command to get this right too?

This would naturally provide a simple solution for issues like golang/dep#209 (comment)

[ianlancetaylor]

There are no such plans.

Any discussion should take place on golang-dev.

This seems like a set of possible solutions rather than a problem. Do you want to restate this in the form of a problem?

[VojtechVitek]

@ianlancetaylor thanks, let me try:

Problem:
There is no way to bake in VERSION string (such as git describe --tags) into a binary when installing the CLI tool via standard go get -u <pkg/cmd> command.

[ianlancetaylor]

I'm sure I'm missing something, but it seems to me that any version number ought to be set in the master source code. I don't see why I would want the version to depend on the characteristics of the machine where the program happens to be built.

[VojtechVitek]

@ianlancetaylor I understand your point of view.

So, is the recommended practice to commit the VERSION string directly to the source code of the repository (master branch), rather than providing it on the build time?

[ianlancetaylor]

That is what I would do, yes.

[mvdan]

Likely a dup of #22147, which is a more narrow proposal and would not require running arbitrary code. Both seem to be looking at the same root problem.

[VojtechVitek]

You're right, I think it is dup of #22147.