it's recommended to only use libtool for when it's actually necessary and this is really for building cross-platform shared libraries. It will be great for libpd, for instance, but I'm thinking now we don't really need it for desktop Pd.
Yeah and that's largely due to the current layout being recursive,
hmmm.. I don't think that's the reason. currently, there aren't that many Makefiles: /src, /portaudio, /portmidi, /asio, /extra and for each external. aside from that, my build system is also recursive (calling make on pd-lib-builder makefiles for the externals). what's really slow is compiling the individual source files. while a typical .c file in /src takes ~1 second on my build system, it takes significantly longer with libtool. this is easily noticeable when watching the console output. I think it's rather an overhead introduced by libtool but I might be wrong. did you notice that on other platforms?