@dpo, when I compiled the new release of qr_mumps, I linked it with libblastrampoline.
I don't know your use case of QRMumps.jl, but if you want better performance, I suggest loading it with AppleAccelerate.
using AppleAccelerate # always before HSL, QRMumps, or Ipopt
using QRMumps
Related issue in HSL.jl: JuliaSmoothOptimizers/HSL.jl#98