@which errors when function is defined using parametric ComponentArray

[amrods]

does this error with @which belong here?

using ComponentArrays

ca = ComponentArray(x=2.0, y=2.0)

function f(ca::ComponentArray{T}) where T
    sum(ca)
end

julia> @which f(ca)
Error showing value of type Method:
ERROR: UndefVarError: T not defined
Stacktrace:
  [1] show(io::IOContext{IOBuffer}, #unused#::
SYSTEM (REPL): showing an error caused an error
ERROR: UndefVarError: T not defined
Stacktrace:
  [1] show(io::IOContext{IOBuffer}, #unused#::
SYSTEM (REPL): caught exception of type UndefVarError while trying to handle a nested exception; giving up

[jonniedie]

It looks like this has to do with the abbreviated type printing. I found a way to work around it, but I'd like to see what I was actually doing wrong in the first place. I posted about it here,