Compile all tests with -Ycheck:all

[rssh]

Now we have. a few issues in test:compile with -Ycheck:all enabled , among them - type failures in some tests during typing:

java.lang.AssertionError: assertion failed: non-empty constraint at end of typer:  uninstantiated variables: T/T#1987968061, T/T#1372193256, T/T#780576975
 constrained types: 
  [T/T#1987968061]#1987968061
    (expr#834683552: 
      (cps#25.monads#4107.FutureContext/T#22108) ?=> T/T#1987968061
    ): concurrent#444.Future/T#8594[T/T#1987968061]
, 
  [T/T#1372193256]#1372193256
    (expr#666277571: 
      (cps#25.monads#4107.FutureContext/T#22108) ?=> T/T#1372193256
    ): concurrent#444.Future/T#8594[T/T#1372193256]
, 
  [T/T#780576975]#780576975
    (expr#340788695: 
      (cps#25.monads#4107.FutureContext/T#22108) ?=> T/T#780576975
    ): concurrent#444.Future/T#8594[T/T#780576975]
 bounds: 
     T/T#1987968061
     T/T#1372193256
     T/T#780576975
 ordering: , ownedVars = T/T#1987968061, T/T#1372193256, T/T#780576975 while compiling /Users/rssh/work/oss/dotty-cps/dotty-cps-async/jvm/src/test/scala/cps/ASChannel.scala, /Users/rssh/work/oss/dotty-cps/dotty-cps-async/jvm/src/test/scala/cps/ComputationBound.scala, /Users/rssh/work/oss/dotty-cps/dotty-cps-async/jvm/src/test/scala/cps/TestCBSFutureIntegration.scala, /Users/rssh/work/oss/dotty-cps/

Need to find and minimize those tests and send bug reports to the dotty team.