golang
proposal: all, x/build/cmd/relui: automate go directive maintenance in golang.org/x repositories
Abstract
The value of the go directive in golang.org/x repositories is automatically maintained to be at least 1.(N-1).0, where Go 1.N is the most recent major Go release, and Go 1.(N-1) is the previous major Go release.
Background
In the beginning, there was the GOPATH mode and versions of dependencies of golang.org/x repositories weren't explicitly tracked. Go 1.11 introduced the module mode, and over time it became the default mode. All golang.org/x repositories had an initial go.mod file checked in, and that file was maintained manually. This meant that a bug fix or a new feature in one golang.org/x repository didn't benefit another golang.org/x repository until someone chose to manually update that dependency. It also meant that eventual updates sometimes jumped many versions at once to catch up. This was resolved in 2022, when an automated monthly relui workflow began to create tags and update golang.org/x dependencies across all golang.org/x repositories (issue #48523).
At this point there are upwards of 35 golang.org/x repositories. Owners of each repository update the "go" directive manually, ad-hoc, so golang.org/x repositories may receive different levels of "go" directive maintenance. For example, owners of the golang.org/x/mod module wished to use the new-to-Go-1.22 go/version package as soon as Go 1.23 came out, and so its "go" directive was recently updated to "1.22.0". On the other hand, golang.org/x/image hasn't been updated in a while, and its "go" directive is currently still at "1.18", which itself was an upgrade from "1.12" in CL 526895 as part of bringing all golang.org/x repos to use at minimum Go 1.18 language version (issue #60268).
Leaving go directive maintenance to be done entirely manually creates the possibility of some repositories staying on an older Go language version longer. When there's enough of a need to finally upgrade it to a recent Go language version, this requires a change across multiple major Go releases at once, which can be harder to review. Having continuous, smaller incremental upgrades requires creating many CLs for all of golang.org/x repositories every 6 months, which is toilsome if always done manually.
Design
Design document at 69095-x-repo-continuous-go.md.
CC @golang/release.
Change https://go.dev/cl/608955 mentions this issue: design/69095-x-repo-continuous-go.md: add design
Related Issues and Documentation
(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)
This proposal has been added to the active column of the proposals project and will now be reviewed at the weekly proposal review meetings. — rsc for the proposal review group
I think we should perhaps emphasize that once the go.mod go directive is updated to Go version 1.N-1.X, is our policy is going to be that package maintainers in that module should feel free to also break the build at older Go versions. This is implied by the reference to using the go/version package, but should be highlighted.
For example, right now x/telemetry has 1.20 in its go.mod file, but still builds with 1.19 (and this "feature" will still be relied upon by v0.16.2 of gopls, which is the final version of gopls supporting building with 1.19, before #65917 takes effect).
With that said, I think this proposal is good for Go overall. Not only will it reduce the toil of go directive maintenance, but it will also help eliminate significant complexity in these repositories related to build support for older Go versions. Additionally, with the help of all the work that has been done to make it easier to use a recent Go toolchain, I think this policy may indirectly help nudge the ecosystem away from using unsupported versions of Go.
Change https://go.dev/cl/610716 mentions this issue: go.mod: for consistency with other repos, use 1.22.0 in go.mod
Based on the discussion above, this proposal seems like a likely accept. — rsc for the proposal review group
The proposal is https://github.com/golang/go/issues/69095#issue-2490518612.
If/when this proposal is accepted, we should add links to the statement of the new policy from the Go 1 compatibility promise and from the Go release policy, to ensure it is discoverable. (And perhaps from the README or go.mod file in the root of each x/ repo.)
For libraries, I think not aggressively forcing upgrades on dependencies is a good thing, and so is staying compatible for more than 2 versions, when 1.23 is just released for instance, probably 1.20 should still be the most recent "forced" upgrade
So imo go.mod go line should just be the language features, not compiler bug fixes etc... that's handled by toolchain and build in final product and govulncheck.
An example of disruptive forced upgrade is x/tools 0.25 which suddenly jumped form go 1.19 to go 1.22(.0) for seemingly no "need"
Specifically I think a lot of even the newer libraries really only need "go 1.18", ie generics and should stay that way.
That is not to say that people shouldn't be using a recent, supported, fully patched go version (eg 1.22.7 at time of this writing), yet libraries should indicate language issue (ie that they are or are not yet using a new iterator etc) not push a cascade of updates downstream
Edit: also while here I can add my pet peeve: the go line should be language version (ie 1.23) not specific patch level (ie 1.23.0) - until 1.21 it was like that and should imo have stayed that way... semver is perfect for toolchain and specific releases but imo doesn't belong in the go line, that .0 just muddies everything (and looks off to see 1.22.0 when 1.22.7 is out)
An example of disruptive forced upgrade is x/tools 0.25 which suddenly jumped form go 1.19 to go 1.22(.0) for seemingly no "need"
It might appear that there was no need because x/tools was working fine with go1.19 only a few weeks ago. But the fact that it was continuing to build with go1.19, when the only supported Go toolchains at that time were go1.21 and go1.22 (and pre-go1.23), was imposing a significant burden on those of us who work in x/tools and those who work on the toolchain (since they had to be careful not to break x/tools). It has been a significant drag on the whole team for a number of years, and was in fact part of the genesis of the forward compatibility system.
No change in consensus, so accepted. 🎉 This issue now tracks the work of implementing the proposal. — aclements for the proposal review group
The proposal is https://github.com/golang/go/issues/69095#issue-2490518612.
Change https://go.dev/cl/593683 mentions this issue: x/tools: assume go1.22 and simplify
Change https://go.dev/cl/649675 mentions this issue: repos: add AutoTagNextMinorVersion and AutoMaintainGoDirective
Change https://go.dev/cl/649676 mentions this issue: internal/task: add GoDirectiveXReposTasks.{SelectRepos,MaintainGoDirectiveAndMailCL}
Change https://go.dev/cl/649677 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649695 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649419 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649715 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649755 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649378 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649376 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649717 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649377 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649795 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649775 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649696 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649380 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649815 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649835 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649698 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]
Change https://go.dev/cl/649697 mentions this issue: all: upgrade go directive to at least 1.23.0 [generated]