Manopt linesearch produces NaN/Inf on SymmetricPositiveDefinite manifold

[ChrisRackauckas-Claude]

Description

The manifold optimization test in OptimizationBase's cvxtest.jl is failing on Julia 1.11 due to the Manopt linesearch producing NaN/Inf values when optimizing on a SymmetricPositiveDefinite manifold.

Error

ArgumentError: matrix contains Infs or NaNs
Stacktrace:
  [1] chkuplofinite(A::Matrix{Float64}, uplo::Char)
  ...
  [6] exp!(::SymmetricPositiveDefinite{ManifoldsBase.TypeParameter{Tuple{5}}}, q::Matrix{Float64}, p::Matrix{Float64}, X::Matrix{Float64})
  ...
  [14] linesearch_backtrack!(M::SymmetricPositiveDefinite{...}, ...)

Affected Test

• lib/OptimizationBase/test/cvxtest.jl - Manifold optimization with GradientDescentOptimizer on SymmetricPositiveDefinite(5)

Workaround

The test has been temporarily skipped in the CI to unblock other tests.

Notes

This may be an issue with how the gradient is computed or passed to Manopt, or an upstream issue in Manopt.jl/Manifolds.jl when dealing with matrix exponentials on SPD manifolds.