hvcat type piracy breaks Manifolds.jl on Julia 1.10

[mateuszbaran]

Resolving #214 uncovered another issue:

  MethodError: hvcat(::Tuple{Int64, Int64}, ::UniformScaling{Bool}, ::Matrix{Float64}, ::Matrix{Float64}, ::UniformScaling{Bool}) is ambiguous.
  
  Candidates:
    hvcat(rows::Tuple{Vararg{Int64}}, As::Union{AbstractArray, LinearAlgebra.AbstractQ, UniformScaling, LinearMaps.LinearMap}...)
      @ LinearMaps ~/.julia/packages/LinearMaps/6ej60/src/blockmap.jl:165
    hvcat(rows::Tuple{Vararg{Int64}}, A::Union{Number, AbstractArray, UniformScaling}...)
      @ LinearAlgebra ~/hostedtoolcache/julia/1.10.0-beta3/x64/share/julia/stdlib/v1.10/LinearAlgebra/src/uniformscaling.jl:447
  
  Possible fix, define
    hvcat(::Tuple{Vararg{Int64}}, ::Vararg{Union{AbstractArray, UniformScaling}})

See here for CI log: https://github.com/JuliaManifolds/Manifolds.jl/actions/runs/6453880959/job/17518302750?pr=648 .

[dkarrasch]

That is because JuliaLang/julia#51132 hasn't been backported yet. Can you please check on nightly if the issue is present there?

[mateuszbaran]

I've recently stopped running tests of Manifolds.jl on nightly because it fails too often. I'll wait for the next prerelease of Julia then.

[dkarrasch]

Sure, or test the failing test locally, not the entire test suite.

[baggepinnen]

This has broken a lot of functionality in the control-systems packages as well. Aren't methods like this one

Base.vcat(As::Union{LinearMap, UniformScaling, AbstractArray, AbstractQ}...)

super piracy?

I expect this to work

julia> [randn(1,1) I; I randn(1,1)]
2×2 Matrix{Float64}:
 0.791215   1.0
 1.0       -0.779665

But after loading LinearMaps.jl v3.11.1 on julia v1.10-beta3, I get

julia> [randn(1,1) I; I randn(1,1)]
ERROR: MethodError: hvcat(::Tuple{Int64, Int64}, ::Matrix{Float64}, ::UniformScaling{Bool}, ::UniformScaling{Bool}, ::Matrix{Float64}) is ambiguous.

Candidates:
  hvcat(rows::Tuple{Vararg{Int64}}, As::Union{AbstractArray, LinearAlgebra.AbstractQ, UniformScaling, LinearMaps.LinearMap}...)
    @ LinearMaps ~/.julia/packages/LinearMaps/6ej60/src/blockmap.jl:165
  hvcat(rows::Tuple{Vararg{Int64}}, A::Union{Number, AbstractArray, UniformScaling}...)
    @ LinearAlgebra ~/.julia/juliaup/julia-1.10.0-beta3+0.x64.linux.gnu/share/julia/stdlib/v1.10/LinearAlgebra/src/uniformscaling.jl:447

Possible fix, define
  hvcat(::Tuple{Vararg{Int64}}, ::Vararg{Union{AbstractArray, UniformScaling}})

Stacktrace:
 [1] top-level scope
   @ REPL[12]:1

[dkarrasch]

I think this is resolved, right?

               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.10.0 (2023-12-25)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

julia> using LinearAlgebra, LinearMaps
Precompiling LinearMaps
  1 dependency successfully precompiled in 3 seconds

julia> [randn(1,1) I; I randn(1,1)]
2×2 Matrix{Float64}:
 -1.11862  1.0
  1.0      0.63299

[mateuszbaran]

Manifolds.jl works now but type piracy is something that should be avoided.