build error caused by package conflict

[mbutterick]

There’s a build error on debug that’s percolating through to my Travis builds that rely on debug (naturally):

 raco pkg install: packages conflict
  package: rackunit-typed
  package: typed-racket-more
  module path: typed/rackunit/type-env-ext

[AlexKnauth]

This could probably be solved by changing the package entry for rackunit-typed to add a version exception. For racket versions before rackunit-typed existed, it should point to an "empty package."

[AlexKnauth]

I've made a pull request to try to fix this on rackunit-typed:
racket/rackunit#93

[AlexKnauth]

@mbutterick Now with that PR to rackunit-typed merged, that build error should be fixed.