# cabal v1-update Downloading the latest package list from test-local-repo # cabal v2-build Resolving dependencies... Build profile: -w ghc- -O1 In order, the following will be built: - pkg-1.0 (exe:my-exe) (first run) Configuring pkg-1.0... Preprocessing executable 'my-exe' for pkg-1.0.. Building executable 'my-exe' for pkg-1.0.. # pkg my-exe local pkg-1.0 # cabal v2-build Resolving dependencies... cabal: Could not resolve dependencies: [__0] next goal: pkg (user goal) [__0] rejecting: pkg-2.0 (constraint from user target requires ==1.0) [__0] rejecting: pkg-1.0 (constraint from command line flag requires ==2.0) [__0] fail (backjumping, conflict set: pkg) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: pkg (3)