Compiling from tasty omits enabling CC

[hamzaremmal]

Compiler version

d5fec8f

Minimized code

Compile this file normally, it will succeed.

import scala.language.experimental.captureChecking

trait File extends caps.SharedCapability

class Foo:
  def f(file: File^): Iterator[File]^{file} = 
    Iterator.from(List(file))

Then compile it with -from-tastyand it will fail.

Output

-- Error: test.scala:5:29 ------------------------------------------------------
class retainsCap is marked @experimental

Experimental definition may only be used under experimental mode:
  1. in a definition marked as @experimental, or
  2. an experimental feature is imported at the package level, or
  3. compiling with the -experimental compiler flag.

-- Error: test.scala:6:4 -------------------------------------------------------
class retains is marked @experimental

Experimental definition may only be used under experimental mode:
  1. in a definition marked as @experimental, or
  2. an experimental feature is imported at the package level, or
  3. compiling with the -experimental compiler flag.

2 errors found

Expectation

It should not fail the ref check and ask to be in an experimental mode. We already have the scala.language.experimental.captureChecking in scope.

[hamzaremmal]

The root cause is: when we load from tasty, we don't set the needsCaptureChecking in the compilation unit.