Dependencies.md

@@ -257,6 +257,20 @@ It can appear that the problem is in filesystem permissions. Try running Blender
 
 Snap creates readonly file system, so you can't put depencencies into it. The only way known to work reliably is to not use Blender from Snap for Sverchok, if you want to use depencencies. The recommended way is to just download Blender's `tar.xz` from blender.org and unpack it.
 
+## Pip install says that the package is already installed, but Sverchok can't see it
+
+It can appear that you have the package installed into your system-wide or user-wide Python installation, for example into `~/.local/lib/python/...`. Try to run
+
+```
+$ python3.7 -m pip uninstall $PACKAGENAME
+```
+
+(using your system's python, not blender's one), and then install the package again with Blender's python
+
+    $ /path/to/blender/2.xx/python/bin/python3 -m pip install $PACKAGENAME
+
+This time you should see that pip is actually installing package.
+
 ### Other troubles with pip
 If you admit some kind of errors with pip, you can try:      
 Wipe all versions of pip from `2.90\python\lib\site-packages` and then run `2.90\python\bin> ./python.exe -m ensurepip -U`