Resolving dependencies... cabal: Could not resolve dependencies: next goal: language-python (user goal) rejecting: language-python-0.5.4, language-python-0.5.3, language-python-0.5.2, language-python-0.5.0, language-python-0.4.1, language-python-0.4.0, language-python-0.3.4, language-python-0.3.3, language-python-0.3.2, language-python-0.3.1 (constraint from user target requires ==0.3.0) trying: language-python-0.3.0 trying: base-4.9.0.0/installed-4.9... (dependency of language-python-0.3.0) next goal: transformers (dependency of language-python-0.3.0) 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: language-python => 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: language-python => 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: language-python => transformers==0.2.*) Dependency tree exhaustively searched.