Warning: The install command is a part of the legacy v1 style of cabal usage. Please switch to using either the new project style and the new-install command or the legacy v1-install alias as new-style projects will become the default in the next version of cabal-install. Please file a bug if you cannot replicate a working v1- use case with the new-style commands. For more information, see: https://wiki.haskell.org/Cabal/NewBuild Resolving dependencies... Starting miso-examples-1.2.0.0 Building miso-examples-1.2.0.0 Failed to install miso-examples-1.2.0.0 Build log ( /home/builder/.cabal/logs/ghc-8.6.3/miso-examples-1.2.0.0-JqtyT4IElC7LM43JORRhOJ.log ): cabal: Entering directory '/tmp/cabal-tmp-21067/miso-examples-1.2.0.0' Configuring miso-examples-1.2.0.0... Warning: Packages using 'cabal-version: >= 1.10' must specify the 'default-language' field for each component (e.g. Haskell98 or Haskell2010). If a component uses different languages in different modules then list the other ones in the 'other-languages' field. Building miso-examples-1.2.0.0... Warning: No documentation was generated as this package does not contain a library. Perhaps you want to use the --executables, --tests, --benchmarks or --foreign-libraries flags. cabal: No executables and no library found. Nothing to do. cabal: Leaving directory '/tmp/cabal-tmp-21067/miso-examples-1.2.0.0' cabal: Error: some packages failed to install: miso-examples-1.2.0.0-JqtyT4IElC7LM43JORRhOJ failed during the final install step. The exception was: ExitFailure 1