haskell turtle shell script to check NVRs of epel7 packages

el7check.hs

{-# LANGUAGE OverloadedStrings #-}

import Turtle
import Data.Text (words)

rpmspecSrc qf spec = do
  (_res, out) <- procStrict "rpmspec" ["-q", "--srpm", "--undefine=dist", "--qf", qf, spec] empty
  return out

nvr = "%{name}-%{version}-%{release}"

checkPkg :: Turtle.FilePath -> Text -> Shell ()
checkPkg top p = do
  el7 <- testdir $ branchDir "epel7"
  when el7 $ do
    hasSpec <- testfile $ specfile "epel7"
    when hasSpec $ do
      arch <- rpmspecSrc "%{arch}" $ specfile_ "epel7"
      unless (arch == "noarch") $ do
        el7 <- rpmspecSrc nvr (specfile_ "epel7")
        (_, out) <- procStrict "koji" ["latest-pkg", "--quiet", "epel7", p] empty
        when (out /= "") $ do
          let cur = (head . Data.Text.words) out
          when (cur == el7 <> ".el7") $ do
            hasf20 <- testfile $ specfile "f20"
            when hasf20 $ do
              f20 <- rpmspecSrc nvr (specfile_ "f20")
              if (el7 < f20)
                then echo $ el7 <> " < F20 " <> f20
                else do
                f21 <- rpmspecSrc nvr (specfile_ "f21")
                when (el7 < f21) $
                  echo $ el7 <> "< F21 " <> f21
  where
    branchDir brch = top </> fromText p </> brch
    branchDir_ brch = format fp $ branchDir brch
    spec = fromText p <.> "spec"
    specfile brch = branchDir brch </> spec
    specfile_ brch = format fp $ specfile brch

main = sh $ do
  top <- pwd
  arguments >>= mapM_ (checkPkg top)