At least here https://www.freecadweb.org/wiki/CompileOnUnix
Thanks Bernd. This works. To give it a test I simply selected "Concrete Generic" for the matrix and "Calculix Steel" for the reinforcement. I then edit the material and enter yield strength for the reinforcement material and friction angle for the matrix material. The yield strength sticks (turning the "Calculix Steel" into "_Transient_Reinforcement_Material"), but the "Concrete Generic" remains unchanged and the friction angle is not captured).