`LinearAlgebra.BLAS.axpy!` breaks for sparse matrices in Julia 1.9

[goerz]

Maybe this is a case of "you're using it wrong", but the following MWE runs fine on Julia 1.8

using SparseArrays
using LinearAlgebra.BLAS: axpy!  # breaks
# using LinearAlgebra: axpy!  # works

N = 5
sparsity = 0.3
H0 = sprand(ComplexF64, N, N, sparsity)
H1 = sprand(ComplexF64, N, N, sparsity)

axpy!(1.0, H0, H1)

On Julia 1.9 (nightly of 2022-09-06), I get

ERROR: LoadError: MethodError: no method matching strides(::SparseMatrixCSC{ComplexF64, Int64})

Closest candidates are:
  strides(::SubArray)
   @ Base subarray.jl:360
  strides(::Union{Base.ReinterpretArray{T, N, S, A, IsReshaped} where {T, N, A<:Union{SubArray{T, N, A, I, true} where {T, N, A<:DenseArray, I<:Union{Tuple{Vararg{Real}}, Tuple{AbstractUnitRange, Vararg{Any}}}}, DenseArray}, IsReshaped, S}, Base.ReshapedArray{T, N, A} where {T, N, A<:Union{Base.ReinterpretArray{T, N, S, A, IsReshaped} where {T, N, A<:Union{SubArray{T, N, A, I, true} where {T, N, A<:DenseArray, I<:Union{Tuple{Vararg{Real}}, Tuple{AbstractUnitRange, Vararg{Any}}}}, DenseArray}, IsReshaped, S}, SubArray{T, N, A, I, true} where {T, N, A<:DenseArray, I<:Union{Tuple{Vararg{Real}}, Tuple{AbstractUnitRange, Vararg{Any}}}}, DenseArray}}, DenseArray})
   @ Base reinterpretarray.jl:151
  strides(::Base.ReshapedArray)
   @ Base reshapedarray.jl:305
  ...

Stacktrace:
 [1] checkedstride(x::SparseMatrixCSC{ComplexF64, Int64})
   @ LinearAlgebra.BLAS /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/LinearAlgebra/src/blas.jl:178
 [2] vec_pointer_stride
   @ /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/LinearAlgebra/src/blas.jl:171 [inlined]
 [3] vec_pointer_stride
   @ /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/LinearAlgebra/src/blas.jl:170 [inlined]
 [4] axpy!(alpha::Float64, x::SparseMatrixCSC{ComplexF64, Int64}, y::SparseMatrixCSC{ComplexF64, Int64})
   @ LinearAlgebra.BLAS /Applications/Julia-1.9.app/Contents/Resources/julia/share/julia/stdlib/v1.9/LinearAlgebra/src/blas.jl:515
 [5] top-level scope
   @ ~/Desktop/DEBUG/debug2.jl:10

The problem is that in Julia 1.9, different methods get called depending on whether I import axpy! from LinearAlgebra or from LinearAlgebra.BLAS. Maybe you say I should stick to the manual and only ever use LinearAlgebra.axpy!, but the example right there in the manual actually also shows BLAS.axpy!. My assumption was that the two were interchangeable. This seems to have been the case in Julia 1.8, but not in Julia 1.9.

I'd be okay with LinearAlgebra.BLAS only being for dense matrices and LinearAlgebra being for AbstractArrays, as long as that is very clearly documented. Also, the error I got here is not very illuminating. It took me quite a while to find out what was happening here.

[goerz]

For the sake of completeness:

LinearAlgebra.axpy! in this case is handled by https://github.com/JuliaLang/julia/blob/31d4c22f29e9dfa7cbe7d3c4f5212c44c5df7baf/stdlib/LinearAlgebra/src/generic.jl#L1439-L1448

LinearAlgebra.BLAS.axpy! is handled by
https://github.com/JuliaLang/julia/blob/31d4c22f29e9dfa7cbe7d3c4f5212c44c5df7baf/stdlib/LinearAlgebra/src/blas.jl#L511-L518

[N5N3]

but the example right there in the manual actually also shows BLAS.axpy!

If you see the nightly doc, there's no BLAS in the doc example.
LinearAlgebra.BLAS.axpy! === LinearAlgebra.axpy! on 1.8, so the current stable doc has no problem.

As for the error message, I thought no method matching strides( is informative enough to show that you are trying to pass a non-strided array into a function only supports strided array. (see Strided Arrays)

[dkarrasch]

Seems fixed downstream, so I'm closing this.