Resolving dependencies... cabal: Could not resolve dependencies: next goal: secure-sockets (user goal) rejecting: secure-sockets-1.2.9.2, secure-sockets-1.2.9.1, secure-sockets-1.2.9, secure-sockets-1.2.8, secure-sockets-1.2.7, secure-sockets-1.2.6, secure-sockets-1.2.5, secure-sockets-1.2.4, secure-sockets-1.2.3 (constraint from user target requires ==1.2.1) trying: secure-sockets-1.2.1 trying: base-4.9.0.0/installed-4.9... (dependency of secure-sockets-1.2.1) next goal: transformers (dependency of secure-sockets-1.2.1) rejecting: transformers-0.5.2.0/installed-0.5..., transformers-0.5.2.0, transformers-0.5.1.0, transformers-0.5.0.1, transformers-0.5.0.0, transformers-0.4.3.0, transformers-0.4.2.0, transformers-0.4.1.0, transformers-0.3.0.0 (conflict: secure-sockets => transformers==0.2.*) rejecting: transformers-0.2.2.1 (conflict: base==4.9.0.0/installed-4.9..., transformers => base>=2 && <4.8 || >=1.0 && <2) rejecting: transformers-0.2.1.0, transformers-0.2.0.0 (conflict: base==4.9.0.0/installed-4.9..., transformers => base>=2 && <4.3 || >=1.0 && <2) rejecting: transformers-0.1.4.0, transformers-0.1.3.0, transformers-0.1.1.0, transformers-0.1.0.1, transformers-0.0.1.0, transformers-0.0.0.0, transformers-0.5.0.2, transformers-0.4.0.0 (conflict: secure-sockets => transformers==0.2.*) rejecting: transformers-0.2.2.0 (conflict: base==4.9.0.0/installed-4.9..., transformers => base>=2 && <4.6 || >=1.0 && <2) rejecting: transformers-0.1.0.0 (conflict: secure-sockets => transformers==0.2.*) Dependency tree exhaustively searched.