It is picking up the @depracated on the object defined above "show".
scalaz sbt dependency: "org.scalaz" %% "scalaz-core" % "7.1.0-M5"
scala plugin version 0.30.383 (0.30.387 has same symptom)
I noticed that this appears to be intermittent. I took just took the 0.30.387 update. After everything settled, the incorrect deprecation warning was displayed. After closing and reopening file it went away and I thought it may have been fixed and some cache needed to be cleared. It just came back though.