Parametric type deprecation when upgrading to 0.7

While upgrading a package I got the following message:

┌ Warning: convert(::Type{T}, x::Enum{T2}) where {T <: Integer, T2 <: Integer} is deprecated, use T(x) instead.
│ caller = setproperty! at sysimg.jl:19 [inlined]
└ @ Core ./sysimg.jl:19

I don’t know what this is about. The pointed filename and number are from Core and I cannot relate this to a specific line of code in my package.
What would be the common case related with this warning?

If you start julia with julia --depwarn=error you get a stacktrace to the warning/error.


Thanks @fredrikekre.
In this particular case I found that the warning arises when an Enum value value is assigned to a struct field declared as integer. The conversion was implicit in 0.6.