declaring a typealias using a type from a package whose name is identical to the module name causes build errors

[mistermoe]

Issue

declaring the following type alias:

import "github.com/TBD54566975/tbdex-go/tbdex"

//ftl:typealias export
type TbdexMessage = tbdex.Message

and then using it in the tbdex module causes the module's codegen'd main.go to include two imports of the same name e.g.

package main

import (
	"context"

	"github.com/TBD54566975/tbdex-go/tbdex"

	"github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1/ftlv1connect"
	"github.com/TBD54566975/ftl/common/plugin"
	"github.com/TBD54566975/ftl/go-runtime/ftl/reflection"
	"github.com/TBD54566975/ftl/go-runtime/server"

	"ftl/tbdex"
)

running ftl build produces the following error:

info:tbdex: # main
./main.go:30:2: tbdex redeclared in this block
	./main.go:23:2: other declaration of tbdex
./main.go:65:27: too many errors

renaming the import in the source file like so:

import tbdexsdk "github.com/TBD54566975/tbdex-go/tbdex"

//ftl:typealias export
type TbdexMessage = tbdexsdk.Message

produces a different error:

unsupported external type "github.com/TBD54566975/tbdex-go/tbdex.Message"; see FTL docs on using external types: tbd54566975.github.io/ftl/docs/reference/externaltypes/

Potential Solution

when code-gen'ing a module's main.go i think it might be helpful to generate package aliases using a pattern that has a very low likelihood of someone actually using. e.g. __tbdex "github.com/TBD54566975/tbdex-go/tbdex"