UndefVarError in Size method

[fredrikekre]

See https://github.com/JuliaArrays/StaticArrays.jl/pull/448/files#r197977273

Tests currently marked as broken:

StaticArrays.jl/test/core.jl

Lines 137 to 143 in 1b99b91

	# broken, see https://github.com/JuliaArrays/StaticArrays.jl/pull/448#discussion_r197977273
	try
	convert(SVector, [1,2,3])
	catch err
	@test_broken isa(err, ErrorException)
	@test_broken startswith(err.msg, "The size of type `StaticArrays.SArray{Tuple{S},T,1,S} where T where S` is not known.")
	end