Fix failed ghcup upgrade if destination dir doesn't exist

Fixes #109

ghcup-0.0.4.yaml

@@ -28,7 +28,7 @@ toolRequirements:
           - libncurses5
           - libtinfo5
           notes: ''
-        "( >= 20.04 && < 20.10 )":
+        ">= 20.04":
           distroPKGs:
           - build-essential
           - curl
@@ -40,18 +40,6 @@ toolRequirements:
           - libncurses5
           - libtinfo5
           notes: ''
-        "( >= 20.10 )":
-          distroPKGs:
-          - build-essential
-          - curl
-          - libffi-dev
-          - libffi8ubuntu1
-          - libgmp-dev
-          - libgmp10
-          - libncurses-dev
-          - libncurses5
-          - libtinfo5
-          notes: ''
       Linux_CentOS:
         '( >= 7 && < 8 )':
           distroPKGs:

lib/GHCup.hs

@@ -1314,12 +1314,17 @@ upgradeGHCup dls mtarget force pfreq = do
   tmp   <- lift withGHCupTmpDir
   let fn = [rel|ghcup|]
   p <- liftE $ download dli tmp (Just fn)
-  let fullDest = fromMaybe (binDir </> fn) mtarget
-  liftIO $ hideError NoSuchThing $ deleteFile fullDest
+  let destDir = dirname destFile
+      destFile = fromMaybe (binDir </> fn) mtarget
+  lift $ $(logDebug) [i|mkdir -p #{toFilePath destDir}|]
+  liftIO $ createDirRecursive' destDir
+  lift $ $(logDebug) [i|rm -f #{toFilePath destFile}|]
+  liftIO $ hideError NoSuchThing $ deleteFile destFile
+  lift $ $(logDebug) [i|cp #{toFilePath p} #{toFilePath destFile}|]
   handleIO (throwE . CopyError . show) $ liftIO $ copyFile p
-                                                           fullDest
+                                                           destFile
                                                            Overwrite
-  lift $ chmod_755 fullDest
+  lift $ chmod_755 destFile
   pure latestVer