The class name "NotFoundError" was too generic in Alien package - so I renamed it into LibrarySymbolNotFoundError. I also added the missing class comment. I hope the small change does not create too much hazzle ---------------------------------------------------------------------------------------------------------------- Name: Alien-Core-TorstenBergmann.101 Author: TorstenBergmann Time: 14 June 2019, 9:48:43.798137 pm UUID: 796ac3ab-af47-0d00-8f6e-47ed0d723e43 Ancestors: Alien-Core-tbn.100 ------------------------------------------------------------------------------- - done in original SqueakSource version http://www.squeaksource.com/Alien.html as Alien-Core-TorstenBergmann.101.mcz - and for Pharo: https://github.com/pharo-project/pharo/issues/3536 / https://github.com/pharo-project/pharo/pull/3537