Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: haskell-language-server-1.8.0.0 (user goal) [__1] trying: haskell-language-server:+qualifyimportednames [__2] trying: hls-qualify-imported-names-plugin-1.0.1.0 (dependency of haskell-language-server +qualifyimportednames) [__3] next goal: hls-plugin-api (dependency of haskell-language-server) [__3] rejecting: hls-plugin-api-1.5.0.0 (conflict: hls-qualify-imported-names-plugin => hls-plugin-api^>=1.3 || ^>=1.4) [__3] rejecting: hls-plugin-api-1.4.0.0 (conflict: haskell-language-server => hls-plugin-api^>=1.5) [__3] skipping: hls-plugin-api-1.3.0.0, hls-plugin-api-1.2.0.2, hls-plugin-api-1.2.0.1, hls-plugin-api-1.2.0.0, hls-plugin-api-1.1.0.2, hls-plugin-api-1.1.0.1, hls-plugin-api-1.1.0.0, hls-plugin-api-1.0.0.0, hls-plugin-api-0.7.1.0, hls-plugin-api-0.7.0.0, hls-plugin-api-0.6.0.0, hls-plugin-api-0.5.0.1, hls-plugin-api-0.5.0.0, hls-plugin-api-0.4.1.0, hls-plugin-api-0.4.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '^>=1.5' from 'haskell-language-server') [__3] fail (backjumping, conflict set: haskell-language-server, hls-plugin-api, hls-qualify-imported-names-plugin) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: haskell-language-server, hls-plugin-api, haskell-language-server:qualifyimportednames, hls-qualify-imported-names-plugin Try running with --minimize-conflict-set to improve the error message.