`UMFPACK` algorithm fails with sparse arrays

[ytdHuang]

Describe the bug 🐞

The following minimal reproducible example (at least) works for LinearSolve v3.4.0, but not for the latest version of LinearSolve

Minimal Reproducible Example 👇

For LinearSolve v3.4.0:

using SparseArrays
using LinearSolve

A = sprand(ComplexF64, 10, 10, 0.5)
b = rand(ComplexF64, 10)

cache = init(LinearProblem(A, b, UMFPACKFactorization()))
sol = solve!(cache)

Error & Stacktrace ⚠️

However, after I upgrade to the latest version of LinearSolve, the above code raises errors:

cache = init(LinearProblem(A, b, UMFPACKFactorization()))

ERROR: ArgumentError: pointer to the SparseArrays.LibSuiteSparse.cholmod_factor_struct object is null. This can happen if the object has been serialized.

which makes

sol = solve!(cache)

ERROR: type Nothing has no field colptr

Environment (please complete the following information):

• Output of using Pkg; Pkg.status()

LinearSolve v3.14.0

• Output of versioninfo()

Julia Version 1.10.8
Commit 4c16ff44be8 (2025-01-22 10:06 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (x86_64-apple-darwin24.0.0)
  CPU: 12 × Intel(R) Core(TM) i7-8700B CPU @ 3.20GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, skylake)
Threads: 1 default, 0 interactive, 1 GC (on 12 virtual cores)