I am solving a system of linear algebraic equations with a sparse complex matrix in a loop. At each pass through the loop I form the sparse complex matrix out of real sparse matrices. First pass through the loop is okay, on the second pass through the loop the memory allocation goes crazy. Yet, the types of the matrices apparently have not changed. No clue what is going on at the moment.

With 1.5.1 on Windows 10.

Has anyone seen this?

A bit more information:

```
ERROR: LoadError: OutOfMemoryError()
Stacktrace:
[1] Array at .\boot.jl:406 [inlined]
[2] _allocres at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\SparseArrays\src\higherorderfns.jl:233 [inlined]
[3] _noshapecheck_map(::SparseArrays.HigherOrderFns.var"#3#4"{typeof(*),SparseArrays.HigherOrderFns.var"#17#20"{Complex{Float64},SparseArrays.HigherOrderFns.var"#21#24"}}, ::SparseArrays.SparseMatrixCSC{Float64,Int64}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\SparseArrays\src\higherorderfns.jl:164
[4] _shapecheckbc at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\SparseArrays\src\higherorderfns.jl:1025 [inlined]
[5] _copy at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\SparseArrays\src\higherorderfns.jl:1015 [inlined]
[6] _copy at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\SparseArrays\src\higherorderfns.jl:1020 [inlined]
[7] copy at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.5\SparseArrays\src\higherorderfns.jl:1011 [inlined]
[8] materialize at .\broadcast.jl:837 [inlined]
[9] broadcast_preserving_zero_d at .\broadcast.jl:826 [inlined]
[10] * at .\arraymath.jl:52 [inlined]
```

on this line

```
U1 .= ((-omega^2+1im*a0)*M + (1+1im*a1)*K)\F;
```