diff --git a/auxbin/jpm b/auxbin/jpm
index cd3d4f76..ae52ff64 100755
--- a/auxbin/jpm
+++ b/auxbin/jpm
@@ -588,16 +588,20 @@ int main(int argc, const char **argv) {
   (rm manifest)
   (print "Uninstalled."))
 
+(defn- rimraf
+  "Hard delete directory tree"
+  [path]
+  (if is-win
+    # windows get rid of read-only files
+    (os/shell `rmdir /S /Q "` path `"`))
+    (rm path))
+
 (defn clear-cache
   "Clear the global git cache."
   []
   (def cache (find-cache))
   (print "clearing " cache "...")
-  (if is-win
-    # Git for windows decided that .git should be hidden and everything in it read-only.
-    # This means we can't delete things easily.
-    (os/shell (string `rmdir /S /Q "` cache `"`))
-    (rm cache)))
+  (rimraf cache))
 
 (def- default-pkglist (or (os/getenv "JANET_PKGLIST") "https://github.com/janet-lang/pkgs.git"))
 
@@ -632,7 +636,9 @@ int main(int argc, const char **argv) {
   (when (mkdir module-dir)
       (set fresh true)
       (print "cloning repository " repo " to " module-dir)
-      (os/execute ["git" "clone" repo module-dir] :p))
+      (unless (zero? (os/execute ["git" "clone" repo module-dir] :p))
+        (rimraf module-dir)
+        (error (string "could not clone git dependency " repo))))
   (def olddir (os/cwd))
   (try
     (with-dyns [:rules @{}