'stack setup': look for ldconfig in 'sbin's

even if those are not in the PATH.

Author: borsboom

src/Stack/Setup.hs

@@ -490,7 +490,12 @@ getGhcBuild menv = do
     platform <- asks getPlatform
     case platform of
         Platform _ Linux -> do
-            eldconfigOut <- tryProcessStdout Nothing menv "ldconfig" ["-p"]
+            -- Some systems don't have ldconfig in the PATH, so make sure to look in /sbin and /usr/sbin as well
+            sbinEnv <- modifyEnvOverride menv $
+                Map.insert "PATH" $
+                "/sbin:/usr/sbin" <>
+                (maybe "" (":" <>) $ Map.lookup "PATH" (eoTextMap menv))
+            eldconfigOut <- tryProcessStdout Nothing sbinEnv "ldconfig" ["-p"]
             let firstWords = case eldconfigOut of
                     Right ldconfigOut -> mapMaybe (headMay . T.words) $
                         T.lines $ T.decodeUtf8With T.lenientDecode ldconfigOut