Usage of gocovmerge is problematic

[tonistiigi]

The test stages run through https://github.com/wadey/gocovmerge project installed in https://github.com/moby/buildkit/blob/v0.18.2/Dockerfile#L300 .

This is problematic because this project:

• Does not have a go.mod
• Does not have any tags
• Has not received changes in 9 years

The combination of these issues means that we are not able to run tests in old versions anymore as go install will fail, for example, already in go1.21.

docker run -it --rm golang:1.21-alpine

/go # go install "github.com/wadey/gocovmerge@latest"
go: downloading github.com/wadey/gocovmerge v0.0.0-20160331181800-b5bfa59ec0ad
go: finding module for package golang.org/x/tools/cover
go: downloading golang.org/x/tools v0.28.0
go: toolchain upgrade needed to resolve golang.org/x/tools/cover
go: golang.org/x/[email protected] requires go >= 1.22.0 (running go 1.21.13; GOTOOLCHAIN=local)

This will continue happening for our current releases as well. As Go (and x/tools) gets updated, or tests stop working.

We need to either:

• Move away from this project
• Create a fork with go.mod support and commits with pinned minimal go versions.

cc @crazy-max