julia> using LinearAlgebra

julia> I2 = Matrix(I, 2,2); D = Diagonal([2.0*I2, 3.0*I2])
2×2 Diagonal{Array{Float64,2},Array{Array{Float64,2},1}}:
 [2.0 0.0; 0.0 2.0]          ⋅         
         ⋅           [3.0 0.0; 0.0 3.0]

julia> eigvals(Diagonal([2.0*I2, 3.0*I2]))  # SHOULD RETURN ARRAY OF SCALARS!
2-element Array{Array{Float64,1},1}:
 [2.0, 2.0]
 [3.0, 3.0]

julia> eigvecs(D)
ERROR: MethodError: no method matching zero(::Type{Array{Float64,2}})
Closest candidates are:
  zero(::Type{LibGit2.GitHash}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/LibGit2/src/oid.jl:220
  zero(::Type{Pkg.Resolve.VersionWeights.VersionWeight}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/Pkg/src/resolve/VersionWeights.jl:19
  zero(::Type{Pkg.Resolve.MaxSum.FieldValues.FieldValue}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/Pkg/src/resolve/FieldValues.jl:44
  ...
Stacktrace:
 [1] zeros(::Type{Array{Float64,2}}, ::Tuple{Int64,Int64}) at ./array.jl:467
 [2] Array{Array{Float64,2},2}(::UniformScaling{Bool}, ::Tuple{Int64,Int64}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/uniformscaling.jl:317
 [3] eigvecs(::Diagonal{Array{Float64,2},Array{Array{Float64,2},1}}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/diagonal.jl:486
 [4] top-level scope at none:0

julia> eigen(D)
ERROR: MethodError: no method matching isfinite(::Array{Float64,2})
Closest candidates are:
  isfinite(::BigFloat) at mpfr.jl:858
  isfinite(::Missing) at missing.jl:79
  isfinite(::Float16) at float.jl:545
  ...
Stacktrace:
 [1] (::getfield(Base, Symbol("##54#55")){typeof(isfinite)})(::Array{Float64,2}) at ./operators.jl:853
 [2] _any at ./reduce.jl:614 [inlined]
 [3] #any#548 at ./reducedim.jl:655 [inlined]
 [4] any at ./reducedim.jl:655 [inlined]
 [5] #eigen#114(::Bool, ::Bool, ::Function, ::Diagonal{Array{Float64,2},Array{Array{Float64,2},1}}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/diagonal.jl:488
 [6] eigen(::Diagonal{Array{Float64,2},Array{Array{Float64,2},1}}) at /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/diagonal.jl:488
 [7] top-level scope at none:0