$ cat Temp.iuml
@startuml
class {
}
@enduml
$ java -jar /scripts/plantuml.jar `find . -name '*.iuml' | xargs` -teps -charset UTF-8 -graphvizdot `which dot` -v
(0.000 - 81 Mo) 79 Mo - PlantUML Version 7986
(0.002 - 81 Mo) 79 Mo - GraphicsEnvironment.isHeadless() false
(0.007 - 81 Mo) 79 Mo - Setting current dir: .
(0.007 - 81 Mo) 79 Mo - Setting current dir: /Users/user/plantuml-bug-exitcode/.
(0.008 - 81 Mo) 79 Mo - Using charset UTF-8
(0.010 - 81 Mo) 79 Mo - Setting current dir: /Users/user/plantuml-bug-exitcode/.
(0.013 - 81 Mo) 79 Mo - Setting current dir: /Users/user/plantuml-bug-exitcode/.
(0.013 - 81 Mo) 79 Mo - Reading file: ./Temp.iuml
(0.435 - 81 Mo) 70 Mo - Creating file: /Users/kenji/plantuml-bug-exitcode/./Temp.eps
(1.209 - 81 Mo) 76 Mo - Number of image(s): 1
user@host:~/plantuml-bug-exitcode\$ echo $?
0
Temp.eps contains a nice red "Syntax Error?" :-)
Edit : same issue with Version 7991