go.mod does not specify v2 version

[hvastani]

The go.mod file in this repo does not specify the /v2 tag so if this module is imported in any project, it will be imported with +incompatible
From the official documentation (https://github.com/golang/go/wiki/Modules)

The module path (such as module foo/v2) declared at the start of a module's go.mod file is both:
the definitive declaration of that module's identity
the definitive declaration of how that module must be imported by consuming code

A module can import a v2+ package that has not opted in to modules itself. A non-module v2+ package that has a valid v2+ semver tag will be recorded with an +incompatible suffix in the importing module's go.mod file. The +incompatible suffix indicates that even though the v2+ package has a valid v2+ semver tag such as v2.0.0, the v2+ package has not actively opted in to modules and hence that v2+ package is assumed to have not been created with an understanding of the implications of Semantic Import Versioning and how to use major versions in import paths. Therefore, when operating in module mode, the go tool will treat a non-module v2+ package as an (incompatible) extension of the v1 version series of the package and assume the package has no awareness of Semantic Import Versioning, and the +incompatible suffix is an indication that the go tool is doing so.

Tested this on centos linux and saw this in my go.mod file
github.com/shirou/gopsutil v2.18.12+incompatible
When I tested this, the current tag was 2.19.03
My go version
go version go1.11 linux/amd64

[Lomanic]

Looks like we would need a /v2 in the import path for it to be not flagged as incompatible (github.com/shirou/gopsutil/v2/...), using a v2 branch it seems according to https://research.swtch.com/vgo-module#from_repository_to_modules

[shirou]

I am not familiar with mod yet, but I think go module can adapt git tag and gopsutil already has version aware git tags. And I don't want to version package directory like gopsutil/v2/disk/disk_linux.go

[ppmathis]

Please note that aside of breaking Go module standards as mentioned earlier in this issue, this repository also actively breaks the semantic versioning standard due to the patch version containing leading zeroes:

Quote from SemVer paragraph 2: A normal version number MUST take the form X.Y.Z where X, Y, and Z are non-negative integers, and MUST NOT contain leading zeroes. X is the major version, Y is the minor version, and Z is the patch version. Each element MUST increase numerically. For instance: 1.9.0 -> 1.10.0 -> 1.11.0.

This leads to the side effect of go get -u github.com/shirou/gopsutil pulling in v2.18.12 instead of v2.19.05, as it is the newest SemVer-compatible version tag. The newest version of gopsutil has to be pulled using go get github.com/shirou/[email protected], which will end up as a pseudo-version in go.mod: v0.0.0-20190601025009-5335e3fd506d

Aside from highly advising you to actually pay attention to the Go modules specification and fixing the incorrect import path, I would at least either re-release the current version tag as v2.19.5 or create a new release as v2.19.6 to ensure users are working with the latest release.

[shirou]

I'm not sure why the go mod thinks v.2.18.12 is newer than v2.19.05. Those are SemVer.

[ppmathis]

I'm not sure why the go mod thinks v.2.18.12 is newer than v2.19.05. Those are SemVer.

Please re-read the paragraph I have quoted from the SemVer specifications page, which states [...] are non-negative integers, and MUST NOT contain leading zeroes. [...]. Your currently used version number is violating the SemVer specification as the patch version, which is 5, is being written with a leading zero as 05.

[shirou]

ah, ok, understood.

So, I tagged v2.19.6 now. Thank you for your comment!

[calvn]

It seems that despite removing the leading zero, go mod still pulls it using the pseudo-version:

› go get github.com/shirou/[email protected]
go: finding github.com/shirou/gopsutil v2.19.7
go: downloading github.com/shirou/gopsutil v0.0.0-20190731134726-d80c43f9c984
go: extracting github.com/shirou/gopsutil v0.0.0-20190731134726-d80c43f9c984

Pulling latest also pins it to v2.18.12 despite having newer releases that are SemVer compatible:

› go get github.com/shirou/gopsutil@latest 

go.mod:

	...
	github.com/shirou/gopsutil v2.18.12+incompatible // indirect
	...

[Xuanwo]

@shirou @calvn

Because there is no v2 in the import path but the tag is v2.19.7, so go mod will use pseudo-version to mark it's a incompatible mod: treat v2.19.7 as a simple string instead of a semver tag.

And pull from latest will get v2.18.12 because v2.18.12 is the last version before adapting go module, the last valid version with import path github.com/shirou/gopsutil

So, there are two options here:

• Do not provide a go.mod file, go will always treat this repo in /v1 but with a high tag.
• Add /v2 into the path to meet go module requirement.

[shirou]

I really don't want to add /v2 path. So just remove go.mod file?

[Lomanic]

Adding a v2 branch might do it, or maybe even default branch could be v2 instead of master (see my first comment and link). But if it means people then would have to import "github.com/shirou/gopsutil/v2/process" I'm also not fond of this. Removing the go.mod is simpler.

[shirou]

I did those combinations

1. remove go.mod
2. changed go.mod to add v2 in module module github.com/shirou/gopsutil -> module github.com/shirou/gopsutil/v2
3. we still have 0 padding git branch like v2.19.05 in repository. so rename those.

on my local pc. but still have incompatible or occurd this error

go: finding github.com/shirou/gopsutil/v2 v2.19.8
build github.com/shirou/test: cannot load github.com/shirou/gopsutil/v2/process: module github.com/shirou/gopsutil@latest (v2.18.12+incompatible) found, but does not contain package github.com/shirou/gopsutil/v2/process

I have tested on just my local pc, so it might be not affected, but those seem no luck.

[shirou]

I am using go version go1.13 linux/amd64. Possibly, it time to start v3 ???

[Xuanwo]

v2 should be added to every import of github.com/shirou/gopsutil.

github.com/shirou/gopsutil/v2 and github.com/shirou/gopsutil are different import path for go modules.

[shirou]

Sorry for the very long time wait. I have released v3 by #938 which has go.mod.