Currently. we can only install a .car file that has a different version than the existing one. Otherwise the install finished success without error but the jar was not overwritten. This issue will not bother user but QA does need this feature. Otherwise, they need to unzip a new studio with every single patch.
Advice: add a -f option in CarMain.java to force overwrite the jar.
https://github.com/Talend/component-runtime/blob/master/component-tools/src/main/java/org/talend/sdk/component/tools/exec/CarMain.java