Go version detection and Go hook install use different effective toolchains

[deadnews]

Summary

Issue #987 was closed by #1457.

This still reproduces in GitHub Actions with prek v0.3.5.

Repro: https://github.com/deadnews/deadnews-template-go/actions/runs/23120666156/job/67154009547?pr=167

Hook: golangci/golangci-lint@v2.11.3

Observed

The workflow shows:

which go
/usr/bin/go

GOTOOLCHAIN=local /usr/bin/go version
go version go1.24.13 linux/amd64

GOTOOLCHAIN=local go version
go version go1.24.13 linux/amd64

/usr/bin/go version
go: downloading go1.26.0 (linux/amd64)
go version go1.26.0 linux/amd64

go version
go version go1.26.0 linux/amd64

prek then logs:

TRACE Using go.mod-derived language_version hook=golangci-lint-full version=>= 1.25.0
TRACE Found matching system go go=/usr/bin/go@1.26.0
TRACE Using system go go=/usr/bin/go@1.26.0

The hook install still fails with:

go: go.mod requires go >= 1.25.0 (running go 1.24.13; GOTOOLCHAIN=local)

Expected

Go version detection and Go hook installation should use the same effective toolchain behavior.

Actual

Go version detection sees /usr/bin/go as 1.26.0, but hook installation runs with GOTOOLCHAIN=local and the same /usr/bin/go is effectively 1.24.13.

Related

• Needs language_version for go with gitleaks whereas pre-commit does not #987
• Extract go version constraint from go.mod #1457