Monad[Free[Id, ?]] cannot be found

[johnynek]

[error] /Users/oscar/oss/cats/free/src/test/scala/cats/free/FreeSuite.scala:18:13: could not find implicit value for parameter e: cats.Monad[[β$1$]cats.free.Free[[A]A,β$1$]]
[error]   implicitly[Monad[Free[Id, ?]]]                                     
[error]             ^                                                                                 
[error] one error found                                                                                 
[error] (freeJVM / Test / compileIncremental) Compilation failed 

Note that there is no problem with implicitly[Monad[Free[Option, ?]]]. I wonder if this could be related to the possible compiler bug found in #2276

[johnynek]

note I discovered this in #2279 where I found that I also could not resolve Defer[Free[Id, ?]]

[ceedubs]

Scalac generally has issues with inference with Id. I think that this is a bit different than #2276. I think that this just requires specialized instances for Id like we've done here for Kleisli.

[kailuowang]

fixed by @barambani in #2383