update

README.md

@@ -21,7 +21,10 @@ The same script (*setup.py*) pulls updates from these repositories
 * extra requirement
 
 ```sh
-$ sudo apt install python-numpy
+# in Kubuntu 20.04 this will install python2 which is used by poky[warrior]
+$ sudo apt install python python-numpy
+# below fixes missing error when compiling the kernel: missing "openssl/bio.h":
+$ sudo apt install libssl-dev
 ```
 
 #### Get sources
@@ -72,4 +75,4 @@ To change git protocol for all Elphel's projects - change the *remote* of this p
 $ git remote -v
 $ git remote set-url ...
 $ ./setup.py
-```
\ No newline at end of file
+```