inherit FiberRef's when a failed fiber joins

core-tests/shared/src/test/scala/zio/ZIOSpec.scala

@@ -2883,6 +2883,19 @@ object ZIOSpec extends ZIOBaseSpec {
           r <- f.join
         } yield assert(r)(equalTo(42))
       },
+      test("propagates FiberRef value even if the effect failed") {
+        for {
+          ref     <- FiberRef.make[Set[String]](Set("parent"))
+          workflow = ref.update(_ + "child") *> ZIO.sleep(2.seconds) *> ZIO.fail(new RuntimeException("Boom!"))
+          f       <- workflow.fork
+          _       <- TestClock.adjust(2.seconds)
+          res     <- f.join.flip
+          set     <- ref.get
+        } yield {
+          assert(res)(isSubtype[RuntimeException](anything)) &&
+          assert(set)(hasSameElements(Set("parent", "child")))
+        }
+      },
       test("deep fork/join identity") {
         val n = 20
         assertZIO(concurrentFib(n))(equalTo(fib(n)))

core/shared/src/main/scala/zio/Fiber.scala

@@ -210,7 +210,7 @@ abstract class Fiber[+E, +A] { self =>
    *   `IO[E, A]`
    */
   final def join(implicit trace: Trace): IO[E, A] =
-    await.unexit <* inheritAll
+    (await <* inheritAll).unexit
 
   /**
    * Maps over the value the Fiber computes.

core/shared/src/main/scala/zio/ZIO.scala

@@ -1272,9 +1272,10 @@ sealed trait ZIO[-R, +E, +A]
 
   /**
    * Returns an effect that races this effect with the specified effect,
-   * returning the first successful `A` from the faster side. If one effect
-   * succeeds, the other will be interrupted. If neither succeeds, then the
-   * effect will fail with some error.
+   * returning the first successful `A` from the faster side and propagates its
+   * all [[FiberRef]] values. If one effect succeeds, the other will be
+   * interrupted. If neither succeeds, then the effect will fail with some
+   * error, and no [[FiberRef]] values will be inherited.
    *
    * WARNING: The raced effect will safely interrupt the "loser", but will not
    * resume until the loser has been cleanly terminated. If early return is
@@ -1287,12 +1288,12 @@ sealed trait ZIO[-R, +E, +A]
       (self.raceWith(that))(
         (exit, right) =>
           exit.foldExitZIO[Any, E1, A1](
-            cause => right.join.mapErrorCause(cause && _),
+            cause => right.await.unexit.mapErrorCause(cause && _) <* right.inheritAll,
             a => right.interruptAs(parentFiberId).as(a)
           ),
         (exit, left) =>
           exit.foldExitZIO[Any, E1, A1](
-            cause => left.join.mapErrorCause(_ && cause),
+            cause => left.await.unexit.mapErrorCause(_ && cause) <* left.inheritAll,
             a => left.interruptAs(parentFiberId).as(a)
           )
       )