diff --git a/CHANGES.txt b/CHANGES.txt
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,5 +1,8 @@
 Changelog for Weeder
 
+0.1.10
+    Make --verbose print out the directory when running commands
+    Don't report semigroups as unused on any platforms
 0.1.9, released 2017-12-07
     Don't report Win32/unix as unused on the alternate platform
 0.1.8, released 2017-12-06
diff --git a/src/Cabal.hs b/src/Cabal.hs
--- a/src/Cabal.hs
+++ b/src/Cabal.hs
@@ -17,7 +17,7 @@
 import Data.List.Extra
 import Data.Tuple.Extra
 import Data.Either.Extra
-import Data.Monoid
+import Data.Semigroup
 import Prelude
 
 
@@ -54,9 +54,12 @@
     ,cabalSections :: [CabalSection]
     } deriving Show
 
+instance Semigroup Cabal where
+    Cabal x1 x2 <> Cabal y1 y2 = Cabal (x1?:y1) (x2++y2)
+
 instance Monoid Cabal where
     mempty = Cabal "" []
-    mappend (Cabal x1 x2) (Cabal y1 y2) = Cabal (x1?:y1) (x2++y2)
+    mappend = (<>)
 
 data CabalSectionType = Library | Executable String | TestSuite String | Benchmark String
     deriving (Eq,Ord)
@@ -90,11 +93,13 @@
     ,cabalPackages :: [PackageName]
     } deriving Show
 
-instance Monoid CabalSection where
-    mempty = CabalSection Library "" [] [] [] []
-    mappend (CabalSection x1 x2 x3 x4 x5 x6) (CabalSection y1 y2 y3 y4 y5 y6) =
+instance Semigroup CabalSection where
+    CabalSection x1 x2 x3 x4 x5 x6 <> CabalSection y1 y2 y3 y4 y5 y6 =
         CabalSection x1 (x2?:y2) (x3<>y3) (x4<>y4) (x5<>y5) (x6<>y6)
 
+instance Monoid CabalSection where
+    mempty = CabalSection Library "" [] [] [] []
+    mappend = (<>)
 
 parseCabal :: FilePath -> IO Cabal
 parseCabal = fmap parseTop . readFile'
diff --git a/src/Check.hs b/src/Check.hs
--- a/src/Check.hs
+++ b/src/Check.hs
@@ -52,7 +52,9 @@
     | (CabalSection{..}, (x1,x2)) <- sections
     , let usedPackages = Set.unions $ map (Set.map fst . hiImportPackageModule . hi) $ x1 ++ x2
     , p <- Set.toList $ Set.fromList cabalPackages `Set.difference` usedPackages
-    , p /= if isWindows then "unix" else "Win32"] -- ignore packages that must be conditional on the other platform
+    , p /= if isWindows then "unix" else "Win32" -- ignore packages that must be conditional on the other platform
+    , p /= "semigroups" -- ignore packages that are often conditional
+    ]
 
 
 warnIncorrectOtherModules :: S -> [Warning]
diff --git a/src/Hi.hs b/src/Hi.hs
--- a/src/Hi.hs
+++ b/src/Hi.hs
@@ -19,7 +19,7 @@
 import Data.Char
 import Data.Hashable
 import Data.List.Extra
-import Data.Monoid
+import Data.Semigroup
 import Data.Functor
 import Util
 import qualified Str as S
@@ -55,9 +55,8 @@
 instance Hashable Hi
 instance NFData Hi
 
-instance Monoid Hi where
-    mempty = Hi mempty mempty mempty mempty mempty mempty mempty mempty mempty
-    mappend x y = Hi
+instance Semigroup Hi where
+    x <> y = Hi
         {hiModuleName = f (?:) hiModuleName
         ,hiImportPackage = f (<>) hiImportPackage
         ,hiExportIdent = f (<>) hiExportIdent
@@ -69,6 +68,10 @@
         ,hiFieldName = f (<>) hiFieldName
         }
         where f op sel = sel x `op` sel y
+
+instance Monoid Hi where
+    mempty = Hi mempty mempty mempty mempty mempty mempty mempty mempty mempty
+    mappend = (<>)
 
 -- | Don't expose that we're just using the filename internally
 newtype HiKey = HiKey FilePath deriving (Eq,Ord,Hashable)
diff --git a/src/Util.hs b/src/Util.hs
--- a/src/Util.hs
+++ b/src/Util.hs
@@ -19,6 +19,7 @@
 import Data.List.Extra
 import Data.Tuple.Extra
 import System.Process
+import System.Directory
 import System.Console.CmdArgs.Verbosity
 import Str(Str)
 import qualified Str as S
@@ -82,12 +83,17 @@
 isPathsModule = isPrefixOf "Paths_"
 
 
+cmdTrace :: FilePath -> [String] -> IO ()
+cmdTrace exe args = whenLoud $ do
+    dir <- getCurrentDirectory
+    putStrLn $ "Running: " ++ showCommandForUser exe args ++ " (in " ++ dir ++ ")"
+
 cmd :: FilePath -> [String] -> IO ()
 cmd exe args = do
-    whenLoud $ putStrLn $ "Running: " ++ showCommandForUser exe args
+    cmdTrace exe args
     callProcess exe args
 
 cmdStdout :: FilePath -> [String] -> IO String
 cmdStdout exe args = do
-    whenLoud $ putStrLn $ "Running: " ++ showCommandForUser exe args
+    cmdTrace exe args
     readCreateProcess (proc exe args) ""
diff --git a/weeder.cabal b/weeder.cabal
--- a/weeder.cabal
+++ b/weeder.cabal
@@ -1,7 +1,7 @@
 cabal-version:      >= 1.18
 build-type:         Simple
 name:               weeder
-version:            0.1.9
+version:            0.1.10
 license:            BSD3
 license-file:       LICENSE
 category:           Development
@@ -26,6 +26,8 @@
     default-language:   Haskell2010
     main-is:            Main.hs
     hs-source-dirs:     src
+    if impl(ghc < 8.0)
+        build-depends: semigroups >= 0.18
     build-depends:
         base >= 4.6 && < 5,
         text,