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 load-font-0.1.0.2 Starting primitive-0.6.4.0 Building primitive-0.6.4.0 Building load-font-0.1.0.2 Failed to install load-font-0.1.0.2 Build log ( /home/builder/.cabal/logs/ghc-8.6.3/load-font-0.1.0.2-DzLfdSkKUmsC2DjUR6MvrF.log ): cabal: Entering directory '/tmp/cabal-tmp-31314/load-font-0.1.0.2' [1 of 1] Compiling Main ( /tmp/cabal-tmp-31314/load-font-0.1.0.2/dist/setup/setup.hs, /tmp/cabal-tmp-31314/load-font-0.1.0.2/dist/setup/Main.o ) Linking /tmp/cabal-tmp-31314/load-font-0.1.0.2/dist/setup/setup ... Configuring load-font-0.1.0.2... Preprocessing library for load-font-0.1.0.2.. Building library for load-font-0.1.0.2.. [1 of 3] Compiling Graphics.UI.Font.LoadCWrapper ( dist/build/Graphics/UI/Font/LoadCWrapper.hs, dist/build/Graphics/UI/Font/LoadCWrapper.o ) [2 of 3] Compiling Graphics.UI.Font.Load ( src/Graphics/UI/Font/Load.hs, dist/build/Graphics/UI/Font/Load.o ) [3 of 3] Compiling Paths_load_font ( dist/build/autogen/Paths_load_font.hs, dist/build/Paths_load_font.o ) src/cbits/font_load.c:8:10: error: fatal error: fontconfig/fontconfig.h: No such file or directory #include ^~~~~~~~~~~~~~~~~~~~~~~~~ | 8 | #include | ^ compilation terminated. `gcc' failed in phase `C Compiler'. (Exit code: 1) cabal: Leaving directory '/tmp/cabal-tmp-31314/load-font-0.1.0.2' Completed primitive-0.6.4.0 cabal: Error: some packages failed to install: fltkhs-themes-0.1.0.7-4GzEYUXy74ltnzX7vyN0q depends on fltkhs-themes-0.1.0.7 which failed to install. load-font-0.1.0.2-DzLfdSkKUmsC2DjUR6MvrF failed during the building phase. The exception was: ExitFailure 1