Hi Mark, > It would be good to avoid these version-specific references, if > possible. Can you help me understand the rationale? Did you find that > there is an incompatibility between the latest stable versions of > 'gtkmm', 'atkmm', 'cairomm', and 'pangomm'? If so, could you help me > understand the nature of that incompatibility? Perhaps it can be > addressed in another way. Its because of ABI incompatibility. The pkg-config for gtkmm, checks for specific ABI versions of atkmm, cairomm and pangomm. > If it turns out that these versioned references are truly unavoidable, > it would be good to add comments next to those references, briefly > explaining the rationale. I have added comment in the code, in v5. Regards, RG.