Friends With a clean HEAD I can't build nofib. See below. What should I do? Thanks Simon (cd nofib; cabal v2-run -- nofib-run --compiler=`pwd`/../_build/stage1/bin/ghc --output=`date -I`) Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: nofib-0.1.0.0 (user goal) [__1] next goal: base (dependency of nofib) [__1] rejecting: base-4.18.0.0/installed-4.18.0.0 (conflict: nofib => base>=4.5 && <4.17) [__1] skipping: base-4.18.0.0, base-4.17.1.0, base-4.17.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=4.5 && <4.17' from 'nofib') [__1] rejecting: 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, 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, nofib) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: base, nofib make: *** [/home/simonpj/code/Makefile-spj:39: nofib] Error 1