warn about patches in third party packages

README.md

@@ -41,9 +41,13 @@ but they will be installed by pip.
 
 ## Installation
 
-```bash
-$ sudo pip3 install ueberzug
-```
+- Install by using pip:  
+  The package is named `ueberzug`  
+- Packages of linux distributions:  
+  At least one packager applies patches to my code.  
+  So if there are issues uninstall it and install it via pip.  
+  Actually I think it's not fine that they call it ueberzug after changing the code.  
+  As bugs introduced by them look like they are part of my work.  
 
 Note: You can improve the performance of image manipulation functions
 by using [pillow-simd](https://github.com/uploadcare/pillow-simd) instead of pillow.