Once again how can you fuss about unstable interfaces on a project that does not have a stable release? You could work with Winehq to create those stable interfaces.
PDB might not be able to fuss, but I will. I recently asked about a way to figure out which version of Wine is in use at run-time because of the recent changes to wine_init()'s prototype. Alexandre appeared quite adamant that he was against introducing any such mechanism.
Wine has a bit of a problem with the Mono project and our much smaller FST project to support VST win32/x86 plugins on linux. It has previously been a self-contained project that did not provide libraries, and whose internal API was not accessed by anyone or anything outside of Wine itself. It now is being used by (at least) 2 projects as a *library*, and it can either accept that role - which implies providing (at least) runtime version info - or reject it, which would be a great shame.
--p