Proper way of injecting fields

[debedb]

I've distilled my question into a repo here. In particular, so I don't have to change signature on my service constructor, I decide to use Parameter object. But it should have all fields I want in the main object anyway, so I just embed. However, this gives me an output shown in README, in particular

missing type:
	- services.SomeServiceType (did you mean to Provide it?)

After stepping through some fx (or is it dig?) code, I thought I realized what the problem is in terms of the missing type.
Having changed it like this, I am now getting an NPE panic essentially:

[Fx] RUN	provide: example.com/fxtest/config.NewConfig()
[Fx] RUN	provide: main.NewServer()
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x0 pc=0x100782d90]

goroutine 1 [running]:
example.com/fxtest/services.(*SomeServiceType).DoSomething(0x0)
	/Users/gregory/g/git/fxtest/services/services.go:26 +0x50
main.(*Server).Start(0x1400008fda0)
	/Users/gregory/g/git/fxtest/main.go:23 +0xe8
main.main.func1(0x1400008fda0)
	/Users/gregory/g/git/fxtest/main.go:31 +0x20
reflect.Value.call({0x1007ed6e0, 0x100842d38, 0x13}, {0x100783cb4, 0x4}, {0x140000b0468, 0x1, 0x1})
	/usr/local/go/src/reflect/value.go:586 +0xa0c
reflect.Value.Call({0x1007ed6e0, 0x100842d38, 0x13}, {0x140000b0468, 0x1, 0x1})

I think I'm way off on the wrong path here, but how do I handle such a case where I would like the fields in the services
module's struct?

[debedb]

The answer seems to be merely using fx.Populate() like so:

package services

import (
	"fmt"

	"example.com/fxtest/config"
	"go.uber.org/fx"
)

type SomeServiceType struct {
	fx.In
	Config *config.Config
}

var SomeService SomeServiceType

func (s *SomeServiceType) DoSomething() {
	fmt.Printf("I am some service doing something with config: %v\n", s.Config)
}

var ServicesModule = fx.Module("services",
	fx.Populate(&SomeService),
)

Without providing the constructor.

Maybe this can be added to the tutorial.