问题
I am on Emacs 24.3.1. I installed the MELPA version of plantuml-mode via
M-x package-install RET plantuml-mode RET.
When I try to turn on plantuml-mode for a buffer, I get the following error:
Wrong type argument: stringp, nil
Trying to find additional installation instructions I looked at the "Commentary" section in the plantuml-mode.el source, but there it only says to require the package, and I am doing that.
How can I fix this problem?
回答1:
After a bit more digging I found the solution to this problem: plantuml-mode won't run unless the variable plantuml-jar-path is set to a non-nil value. Fairly obvious in hindsight, but still easy to get bit by since it isn't mentioned explicitly (at least not anywhere that I could find). For best results, the variable should point to the location of the plantuml.jar file in your file system. In my case:
(setq plantuml-jar-path "/opt/plantuml/plantuml.jar")
Hope this helps someone else at some point.
来源：https://stackoverflow.com/questions/22575080/cant-turn-on-plantuml-mode-in-emacs