Trait stack modification on Function0[Unit]

[PROteinBY]

Please check this page for an example and description: https://stackoverflow.com/questions/58580830/scala-stack-modifications-on-function0

[PROteinBY]

If you define you own Function0[+R] without @specialized it will work.

[som-snytt]

Related literature:

#4996
scala/scala#1173
scala/scala#7672

[PROteinBY]

Related literature:

#4996
scala/scala#1173
scala/scala#7672

My issue is similar to the one described in #4996 but my case is failing in Scala 2.13.1.