Hi.
Normally pyjnius only install if you have java installed. What i see is that JAVA_HOME is not set.
Try echo $JAVA_HOME to see if you have JAVA_HOME variable set. If not find out where is java idk installed and set JAVA_HOME variable.
Also, i will install again in vagrant (this weekend) to see if every thing is ok. I get others people reporting that they can’t get install-app.
Also, tell me how did you install pyjnius. I have been problems when i install from pip install pyjnius. Check, also, if pyjnius is installed in frappe-bench/env/… virtual folder and not globally.
The best way is to install has i told you before.