Install libnetbeans-cvsclient-java by entering the following commands in the terminal:
sudo apt update sudo apt install libnetbeans-cvsclient-java
NetBeans CVS Client library
The CVS Client library is a pure Java implementation of a CVS client protocol. It allows to access CVS servers without setting up an external cvs program. It is used in the javacvs module in NetBeans and in other projects, such as SmartCVS and Maven SCM.