Failing require("foo", host=self.host) could get a better error message

[Ma27]

So apparently batou 2.5 fixed something around self.require("foo", host=self.host) since I got the following error messages on a batou deployment that worked perfectly fine before when upgrading to 2.5.1 (for FC employees, see FC-41525):

ERROR: Unsatisfied resource requirements
    Resource "source" required by application,applicationqueueshutdown,applicationqueuestartup,application,applicationsourcecleanup
Reporting hosts: customerstag01, customerstag00
  Not reporting: customerstag11, customerstag10

ERROR: Unsatisfied resource requirements
    Resource "source" required by applicationsourcecleanup,application,applicationqueueshutdown,applicationqueuestartup,application
Reporting hosts: customerstag10
  Not reporting: customerstag11, customerstag00, customerstag01

After a bit of fiddling with pdb I found out that the issue was a self.require("source", host=self.host) that should've been a self.require("source"). Same for another call with reverse=True.

I haven't checked whether the deployment triggered an edge-case or if that was a general issue on batou 2.4.

Anyways, the error above is the same as for "I required something, but that doesn't exist at all" which was quite misleading here since I've seen that each requirement was correct and pdb confirmed that for each subscriber there was a corresponding resource registered in batou.

So what I'd like to have is an error that tells me that the requirement on applicationqueuestartup/applicationqueueshutdown was not satisfied because there's a host=self.host clause.
Also, the requirements from application/applicationsourcecleanup were OK, so these shouldn't even appear in that message in the first place IMHO.