go.mod: split the indirect packages

[zchee]

Split the indirect packages of go.mod.

After go1.17, all indirect packages are listed in the go.mod file.

In addition, has been introduced the ability to list indirect packages separately.
Split the indirect package to make the dependency packages clearer.

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This pull request is no-op to codes, just formatted.

[tonistiigi]

Are there some links we can read up on about this being the recommended way to layout go.mod now?

[zchee]

@tonistiigi I will look for it later, but at least it is specified out below.

https://golang.org/ref/mod#go-mod-file-go

At go 1.17 or higher:

• The go.mod file includes an explicit require directive for each module that provides any package transitively imported by a package or test in the main module. (At go 1.16 and lower, an indirect dependency is included only if minimal version selection would otherwise select a different version.) This extra information enables module graph pruning and lazy module loading.
• Because there may be many more // indirect dependencies than in previous go versions, indirect dependencies are recorded in a separate block within the go.mod file.

Actually,

indirect dependencies are recorded in a separate block within the go.mod file.

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That means, as a premise, when go.mod go directive is go1.17:
If you adding some dependency package with go get, and already separated blocks, will same result to the this pull request.
This behavior has become a specification of the go command.

See also: https://golang.org/ref/mod#graph-pruning

[zchee]

@tonistiigi Also,

https://golang.org/doc/go1.17#go-command

Because the number of explicit requirements may be substantially larger in an expanded Go 1.17 go.mod file, the newly-added requirements on indirect dependencies in a go 1.17 module are maintained in a separate require block from the block containing direct dependencies.

[tonistiigi]

SGTM

[tonistiigi]

@zchee This needs rebase

[zchee]

@tonistiigi done

[thaJeztah]

Do we know if the second require block is ignored by older go version, or is it also used?

The thing that surprised me a bit is that some of these // indirect were not automatically created by go mod, but were manually added to force using a more current version.

I think this import for example (based on the comment) is a manual override, but also github.com/cpuguy83/go-md2man/v2, and some others. I'd have expected go to only put the "automatically collected" imports in the second block, but to keep the "manual overrides" to be in the first block.

[zchee]

@thaJeztah make sense. will check go1.17 go mod behavior and send PR again

[zchee]

@thaJeztah created PR: #2348