Ensure existence of static build dir

.gitignore

@@ -12,6 +12,6 @@ app/static/custom_config
 app/static/bangs
 
 # pip stuff
-build/
+/build/
 dist/
 *.egg-info/

app/__init__.py

@@ -101,7 +101,12 @@ for cb_dir in cache_busting_dirs:
         full_cb_path = os.path.join(full_cb_dir, cb_file)
         cb_file_link = gen_file_hash(full_cb_dir, cb_file)
         build_path = os.path.join(app.config['BUILD_FOLDER'], cb_file_link)
-        os.symlink(full_cb_path, build_path)
+
+        try:
+            os.symlink(full_cb_path, build_path)
+        except FileExistsError:
+            # Symlink hasn't changed, ignore
+            pass
 
         # Create mapping for relative path urls
         map_path = build_path.replace(app.config['APP_ROOT'], '')

app/static/build/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

run

@@ -12,8 +12,6 @@ SUBDIR="${1:-app}"
 export APP_ROOT="$SCRIPT_DIR/$SUBDIR"
 export STATIC_FOLDER="$APP_ROOT/static"
 
-rm -rf $STATIC_FOLDER/build
-
 # Check for regular vs test run
 if [[ "$SUBDIR" == "test" ]]; then
     # Set up static files for testing