Unable to install breakpoint even if line number set to be generated

I am unable to get breakpoints to work for a html5 project running on WildFly.

I tried to verify JBIDE-20804 so I created the html5 project from central, set a breakpoint in MemberService.listAllMembers() (line 72) and then selected Debug on server -> WildFly. The server was started in debugging mode and the project started deploying, but then I got an error:
Unable to install breakpoint in org.jboss.tools.example.html5.rest.MemberService$$$view3 due to missing line number attributes. Modify compiler options to generate line number attributes.
Reason: Absent Line Number Information

I checked and this option was checked in Preferences -> Java -> Compiler. Also, I even checked the project settings (.settings/org.eclipse.jdt.core.prefs) and it has:
org.eclipse.jdt.core.compiler.debug.lineNumber=generate

This happened to me on Mac with WildFly 8, 9 and 10. And psrna checked this for me on Linux and the result was the same.

I'm not really sure which component this should belong to, it looks like an upstream issue.