InexactError needs more explanation

[dpsanders]

InexactErrors have often been a source of mystery, e.g.

julia> type MyTest{T}
           value::T
       end

julia>

julia> MyTest{Int}(3.1)
------ InexactError -------------------- Stacktrace (most recent call last)

 [1] — MyTest{Int64}(::Float64) at REPL[1]:2

InexactError()

Would it be possible to say something more helpful, like

InexactError: Trying to convert 3.1 to Int64

[timholy]

Someone just needs to implement #18521. Volunteering? 😉

[tkelman]

Closing as dup