Resolving dependencies... Configuring base-prelude-1.3... Configuring base-compat-0.10.4... Building base-prelude-1.3... Building base-compat-0.10.4... Installed base-prelude-1.3 Configuring clock-0.7.2... Building clock-0.7.2... Installed base-compat-0.10.4 Configuring fgl-5.6.0.0... Building fgl-5.6.0.0... Installed clock-0.7.2 Configuring hashable-1.2.7.0... Building hashable-1.2.7.0... Installed hashable-1.2.7.0 Configuring integer-logarithms-1.0.2.2... Building integer-logarithms-1.0.2.2... Installed integer-logarithms-1.0.2.2 Configuring primitive-0.6.4.0... Building primitive-0.6.4.0... Installed fgl-5.6.0.0 Configuring algebraic-graphs-0.2... Building algebraic-graphs-0.2... Installed primitive-0.6.4.0 Configuring extra-1.6.11... Building extra-1.6.11... Installed algebraic-graphs-0.2 Configuring unordered-containers-0.2.9.0... Building unordered-containers-0.2.9.0... Installed extra-1.6.11 Configuring scientific-0.3.6.2... Building scientific-0.3.6.2... Installed unordered-containers-0.2.9.0 Configuring hexml-0.3.4... Installed scientific-0.3.6.2 Configuring attoparsec-0.13.2.2... Building hexml-0.3.4... Building attoparsec-0.13.2.2... Installed hexml-0.3.4 Installed attoparsec-0.13.2.2 Configuring html-entities-1.1.4.2... Building html-entities-1.1.4.2... Installed html-entities-1.1.4.2 Configuring pangraph-0.2.0... Building pangraph-0.2.0... Failed to install pangraph-0.2.0 Build log ( /home/builder/.cabal/logs/ghc-8.4.3/pangraph-0.2.0-D6Ytg0Md9tvEoTCcv5vKNm.log ): cabal: Entering directory '/tmp/cabal-tmp-30598/pangraph-0.2.0' Configuring pangraph-0.2.0... Preprocessing library for pangraph-0.2.0.. Building library for pangraph-0.2.0.. [ 1 of 16] Compiling Pangraph ( src/Pangraph.hs, dist/build/Pangraph.o ) src/Pangraph.hs:73:10: error: Not in scope: type constructor or class ‘Alga.ToGraph’ Perhaps you meant ‘Alga.Graph’ (imported from Algebra.Graph.Class) Module ‘Algebra.Graph.Class’ does not export ‘ToGraph’. | 73 | instance Alga.ToGraph Pangraph where | ^^^^^^^^^^^^ cabal: Leaving directory '/tmp/cabal-tmp-30598/pangraph-0.2.0' cabal: Error: some packages failed to install: pangraph-0.2.0-D6Ytg0Md9tvEoTCcv5vKNm failed during the building phase. The exception was: ExitFailure 1