Setup.hs

import Distribution.PackageDescription (emptyHookedBuildInfo)
import Distribution.Simple
import System.Directory (copyFile, doesFileExist)
import System.Exit
import System.Process (readProcessWithExitCode)

main =
    defaultMainWithHooks
        simpleUserHooks{preBuild = preBuildChecks}
  where
    -- \| Checks that Imagemagick and LaTeX are available
    preBuildChecks _ _ = do
        mapM_ checkDependency ["magick", "pdflatex"]
        return emptyHookedBuildInfo

    checkDependency :: String -> IO ()
    checkDependency dependency = do
        (result, _, _) <- readProcessWithExitCode dependency ["-version"] ""
        case result of
            ExitFailure 127 -> putStrLn ("Error Message: " ++ dependency ++ " is NOT available. Please ensure it is on your path.") >> exitFailure
            _ -> putStrLn (dependency ++ " has been installed.")