3.3.0-RC4 `-Wunused:imports` false positive for imports that are only used in imports

[Lasering]

Compiler version

3.3.0-RC4

Minimized code

Define some givens in a base package:

package com.base

import java.net.URI
import io.circe.Codec
import io.circe.derivation.Configuration

given Configuration = ???
given Codec[URI] = ???

Import those givens explicitly by type in another package:

package com.base.models

import java.net.URI
import io.circe.Codec
import io.circe.derivation.{Configuration, ConfiguredCodec}
import com.base.{given Configuration, given Codec[URI]}

case class Operator(url: Option[URI]) derives ConfiguredCodec

Output

The compiler gives the following warnings:

import io.circe.Codec
                ^^^^^
                unused import
import io.circe.derivation.{Configuration, ConfiguredCodec}
                            ^^^^^^^^^^^^^
                            unused import
import com.base.{given Configuration, given Codec[URI]}
                                      ^^^^^^^^^^^^^^^^
                                      unused import

Expectation

No warning should be emitted. Please note:

• Configuration and Codec were only imported to be used in import com.base.{given Configuration, given Codec[URI]} the rest of the file does not use those types.
• the method ConfiguredCodec.derived expects a Configuration instance to be in the implicit scope.
• Codec[URI] will be used while deriving the ConfiguredCodec.

[jchyb]

One file, no dependency minimization:

package circelike {
  import java.net.URI
  import scala.compiletime.{erasedValue, summonInline}
  import scala.deriving.Mirror

  type Codec[T]
  type Configuration
  trait ConfiguredCodec[T]
  object ConfiguredCodec:

    inline final def derived[A](using conf: Configuration)(using
      inline mirror: Mirror.Of[A]
    ): ConfiguredCodec[A] =
      new ConfiguredCodec[A]:
        val codec = summonInline[Codec[URI]] // simplification
}

package foo {
  import java.net.URI
  import circelike.{Codec, Configuration}

  given Configuration = ???
  given Codec[URI] = ???
}

package bar {
  import java.net.URI
  import circelike.Codec
  import circelike.{Configuration, ConfiguredCodec}
  import foo.{given Configuration, given Codec[URI]}

  case class Operator(url: URI) derives ConfiguredCodec
}