When running scripted from an sbt 0.13.16 build, cross building against sbt 1.0, the Scala 2.12 compiler bridge seems to be being recompiled for every scripted test (that does compilation). It doesn't happen when running scripted against sbt 0.13.16 with sbt 0.13.16, just when it's a different sbt (or probably rather scala) version.

Example output shown in every scripted test that invokes compile:

[info] [info] Non-compiled module 'compiler-bridge_2.12' for Scala 2.12.3. Compiling...
[info] [info]   Compilation completed in 9.008s.

9 seconds per scripted test (a lot longer on travis) is not ideal.