`Resource#allocate` that fails produces `reportFailure` under timeout

[FireFoxIL]

I have recently discovered a strange behaviour while trying to use .timeout on the Resource of the Client.run(_) from http4s. As I later investigated, the issue has nothing to do with http4s, ember or fs2.

//> using scala 3
//> using dep org.typelevel::cats-effect:3.7.1

import cats.effect.*
import cats.effect.syntax.temporal.*
import scala.concurrent.duration.*

object ReproMakeBug extends IOApp {
  override def run(args: List[String]): IO[ExitCode] =
    Resource
      .make(IO.raiseError[Unit](new RuntimeException("boom")))(_ => IO.unit)
      .timeout(300.millis)
      .use(_ => IO.unit)
      .handleErrorWith { e =>
        IO.println(s"[handled] ${e.getClass.getName}: ${e.getMessage}")
      }
      .as(ExitCode.Success)
}

This code produces two error mesages: one defined in the code and one by IOApp.reportFailure. For me this is strange, because the error is handled and I expect that reportFailure should not be called.

Code with eval doesn't produce such message:

//> using scala 3
//> using dep org.typelevel::cats-effect:3.7.1

import cats.effect.*
import cats.effect.syntax.temporal.*
import scala.concurrent.duration.*

object ReproEvalControl extends IOApp {

  override def run(args: List[String]): IO[ExitCode] =
    Resource
      .eval(IO.raiseError[Unit](new RuntimeException("boom")))
      .timeout(300.millis)
      .use(_ => IO.unit)
      .handleErrorWith { e =>
        IO.println(s"[handled] ${e.getClass.getName}: ${e.getMessage}")
      }
      .guarantee(IO.sleep(600.millis))
      .as(ExitCode.Success)
}

[reardonj]

For extra weirdness, adding a cede brings the report back:

//> using scala 3
//> using dep org.typelevel::cats-effect:3.7.1

import cats.effect.*
import cats.effect.syntax.temporal.*
import scala.concurrent.duration.*

object ReproEvalControl extends IOApp {

  override def run(args: List[String]): IO[ExitCode] =
    Resource
      .eval(IO.cede >> IO.raiseError[Unit](new RuntimeException("boom")))
      .timeout(300.millis)
      .use(_ => IO.unit)
      .handleErrorWith { e =>
        IO.println(s"[handled] ${e.getClass.getName}: ${e.getMessage}")
      }
      .guarantee(IO.sleep(600.millis))
      .as(ExitCode.Success)
}

java.lang.RuntimeException: boom
	at ReproEvalControl$.run$$anonfun$1(Main.scala:12)
	at >> @ ReproEvalControl$.run(Main.scala:12)
[handled] java.lang.RuntimeException: boom

[durban]

Is this different from #2962?

[reardonj]

I guess since Resource's Concurrent doesn't override racePair to use the effect's implementation it doesn't go through IO's racePair, which should avoid this.

[durban]

Yeah, at first glance this seems like a duplicate of #2962, just for Resource. It could probably be "solved" the same way (and is similarly unfixable in the general case).

Also related: #3085.