I just picked up a copy of “Parallel and Concurrent Programming in Haskell”. And I’m trying to follow the instructions on p.4 for getting the examples installed, but having trouble: [23-11-10 9:49] dbanas@Davids-Air-M2:~/prj % cabal unpack parconc-examples Downloading parconc-examples-0.4.8 Downloaded parconc-examples-0.4.8 Unpacking to parconc-examples-0.4.8/ [23-11-10 9:50] dbanas@Davids-Air-M2:~/prj % pushd parconc-examples-0.4.8 ~/prj/parconc-examples-0.4.8 ~/prj ~ [23-11-10 9:50] dbanas@Davids-Air-M2:~/prj/parconc-examples-0.4.8 % cabal install --only-dependencies cabal: Could not resolve dependencies: [__0] trying: parconc-examples-0.4.8 (user goal) [__1] next goal: base (dependency of parconc-examples) [__1] rejecting: base-4.17.2.0/installed-4.17.2.0 (conflict: parconc-examples => base>=4.5 && <4.14) [__1] skipping: base-4.19.0.0, base-4.18.1.0, base-4.18.0.0, base-4.17.2.0, base-4.17.1.0, base-4.17.0.0, base-4.16.4.0, base-4.16.3.0, base-4.16.2.0, base-4.16.1.0, base-4.16.0.0, base-4.15.1.0, base-4.15.0.0, base-4.14.3.0, base-4.14.2.0, base-4.14.1.0, base-4.14.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=4.5 && <4.14' from 'parconc-examples') [__1] rejecting: base-4.13.0.0, base-4.12.0.0, base-4.11.1.0, base-4.11.0.0, base-4.10.1.0, base-4.10.0.0, base-4.9.1.0, base-4.9.0.0, base-4.8.2.0, base-4.8.1.0, base-4.8.0.0, base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1, base-4.6.0.0, base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0, base-4.3.1.0, base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0, base-4.1.0.0, base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from non-upgradeable package requires installed instance) [__1] fail (backjumping, conflict set: base, parconc-examples) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: base, parconc-examples Thanks, -db