Update the go.mod file to include a /v3 at the end of the module path in the module directive

[Delphier]

go version: 1.11.4
go.mod enabled.

go get github.com/labstack/echo can't get the correct latest version. to get the version 3.3.5, but latest version is 3.3.8.

in the latest golang modules wiki, need to Update the go.mod file to include a /v3 at the end of the module path in the module directive.

please review:

https://github.com/golang/go/wiki/Modules#releasing-modules-v2-or-higher

[kodawah]

pinging @vishr since this is affecting a few of my projects as well ^^

[vishr]

Can you guys send a PR?
@im-kulikov Can you take care of this?

[im-kulikov]

@vishr yeah)

[alexaandru]

For the record, there's quite a bit of chatter about this in PR #1253
The short answer is: no, that is not so simple (just adding a /v3 suffix to existing v3.x line).

I did a tiny POC here: https://github.com/alexaandru/modules that replicated this precise issue: 1. have some V2+ branch; 2. add go.mod to it without suffix 3. add suffix later. The result when you try to import it (with /v2 suffix as it should be) is:

$ go build
go: downloading github.com/alexaandru/modules/v2 v2.2.0
build github.com/alexaandru/foobar: cannot find module for path github.com/alexaandru/modules/v2

so, half broken. It does resolve to the proper tag (v2.2.0, the last in the V2 line) however it also throws a cannot find module. The only resolution is to push the next vN, and release the vN at the same time with the vN.x.y tag (also tested on the POC repo and that worked as expected).

To wrap it up, we're working on it and hope to get it back working ASAP.

[Delphier]

can we remove go.mod file on v3? start use go.mod from v4.

[im-kulikov]

@Delphier The problem is not in go.mod

[alexaandru]

@im-kulikov actually the problem is in go.mod - the fact that it was introduced from the start on a v2+ repo without the /vN suffix. I'm just not sure if removing it would fix the problem... need to try it out on my POC.

Just tested on my POC (https://github.com/alexaandru/modules), deleting go.mod will still not fix it. An app using Go modules will still fetch the version before go.mod was introduced (even if later, go.mod was removed, it still remains in history).

So V4 is the only way to go at this point.

[im-kulikov]

@alexaandru I guess I didn't put it right. I meant that deleting the file doesn't solve the problem.

[Delphier]

i fork echo and tested it:

- delete go.mod and go.sum
- release 3.3.10

run go get or go build or go mod tidy , the verson in go.mod is v3.3.10+incompatible.
Seems to be able to solve this problem temporarily.

[im-kulikov]

Don't quite understand how removing go.mod solved the problem?

[im-kulikov]

You can repeat the experiment without deleting the file.. I suppose the result will be the same..

[Delphier]

Actually in go module mode:

module github.com/labstack/echo = module github.com/labstack/echo/v1
import github.com/labstack/echo = import github.com/labstack/echo/v1

just v1 is omitted.

becase tagged v1.x release with go.mod not found, v3.3.5 is last release without go.mod, so it is selected.
from golang help: Module compatibility and semantic versioning

Code written before the semantic import versioning convention was introduced may use major versions v2 and later to describe the same set of unversioned import paths as used in v0 and v1. To accommodate such code, if a source code repository has a v2.0.0 or later tag for a file tree with no go.mod, the version is considered to be part of the v1 module's available versions and is given an +incompatible suffix when converted to a module version, as in v2.0.0+incompatible. The +incompatible tag is also applied to pseudo-versions derived from such versions, as in v2.0.1-0.yyyymmddhhmmss-abcdefabcdef+incompatible.

[im-kulikov]

hm.. it make sense.. @alexaandru what you think?

[alexaandru]

Sounds good to me, it can't make things worse :-) Worst case scenario: it still pulls v3.3.5, at least that's how it did in my POC, but seems that @Delphier got a different outcome. I'll give it a try...

[alexaandru]

Yes, this fixed it! Thanks @Delphier @im-kulikov ! :-) Please confirm it works on your end as well, so we can close this ticket. Thanks again!

[cubic3d]

@alexaandru works fine for now, I get github.com/labstack/echo v3.3.10+incompatible

[alexaandru]

Awesome, thank you very much @cubic3d ! Closing this.

[Delphier]

works fine 😋

[alexaandru]

Thank you @Delphier :-)

[im-kulikov]

yay... it's work!

github.com/labstack/echo v3.3.10+incompatible // indirect

[alexaandru]

Thanks @im-kulikov ! :)

[louiemiranda]

Hi, just trying to understand.

When I go get labstack/echo.

I get the following on go.mod

github.com/labstack/echo v3.3.10+incompatible

I was hoping to get the latest version of 4.x.

When I tried...

go get -u github.com/labstack/echo@v4.1.17
go get github.com/labstack/echo@v4.1.17: github.com/labstack/echo@v4.1.17: invalid version: module contains a go.mod file, so major version must be compatible: should be v0 or v1, not v4

I don't get it.

[Delphier]

@louiemiranda Change github.com/labstack/echo to github.com/labstack/echo/v4 in go.mod and *.go file.

[louiemiranda]

thanks ! will try