1.11.0 causes errors with //go:generate packer-sdc mapstructure-to-hcl2

[NorseGaud]

Details: hashicorp/packer-plugin-sdk#128

[apparentlymart]

Hello! Thanks for reporting this.

I also saw a problem like this when running an old build of "stringer" in a codebase containing go-cty.

In the interests of making this searchable, I'll copy the error message you saw from the other issue into here:

Unexpected package creation during export data loading

The problem seems to be upstream, tracked in golang/go#51629. It will occur as soon as there's at least one package in your codebase which uses Go 1.18 type parameters, and so I guess go-cty was the first module in your dependency tree to begin using those features. If another dependency had happened to start using type parameters first then it would've been that upgrade which would've encountered this error.

The fix was in the golang.org/x/tools module, which your code generator seems to depend on. If that's true then I think the resolution steps would be to:

• Upgrade to golang.org/x/tools v0.1.12
• If you're using a pre-built executable of your generator in your GOBIN directory, then you'll need to rebuild that with the upgraded golang.org/x/tools to make it work. If you are running it with go run ... then it should automatically notice that the dependency has changed and so rebuild it.

This module doesn't itself depend on golang.org/x/tools (directly or indirectly), so I can't force a newer version of that module through a change in this repository. The dependency must unfortunately be upgraded in the module which contains the tool, because it's the tool that depends on golang.org/x/tools. Based on what you showed in the linked issue, I guess that means that the dependency from packer-plugin-sdk is the one that needs to be updated here, because that seems to be the module which contains this "mapstructure-to-hcl2" tool.