Converted from http://www.assembla.com/spaces/clojure/tickets/148

scgilardi said: It's saying that the symbol com.howardlewisship.cascade.test-views/write already resolves to #���clojure.contrib.pprint/write, so you can't def a new write in com.howardlewisship.cascade.test-views.

What do you propose for an alternate wording of the error message here?

I think the issue is that only one side of the conflict is reported in the error, so if you get this kind of error in the middle of a large project it can be hard to figure out which namespace is conflicting. Take a toy example:

user=> (ns foo)
foo=> (def foobar 42)
foo=> (ns bar)
bar=> (def foobar 0)
bar=> (ns problem)
problem=> (refer 'foo)
problem=> (refer 'bar)
java.lang.IllegalStateException: foobar already refers to: #'foo/foobar in namespace: problem (NO_SOURCE_FILE:0)

In this case it would be best if the error said something like:

"Conflict referring to #'bar/foobar in #<Namespace problem> because foobar already refers to: #'foo/foobar."

This way the error message clearly identifies the location of the conflict, and the locations of the two conflicting vars.

Hopefully this helps clarify. I think I see where to fix it in warnOrFailOnReplace on line 88 of src/jvm/clojure/lang/Namespace.java, and this reminds me I need to send in a CA so I can pitch in next time...

It looks like the true conflict is in test-views, not in dom. A small example of the line number breakage showing the problem on master (1.3) would be very helpful.