A libdir autoconf template would be awesome to have though. Building C or C++ objects for Pd isn't hard. What about flext makes things so complicated? In the process of making that template Makefile, I realized that autotools is really rarely needed for externals. Only really when there are a lot of library dependencies.
flext is a library dependecy!
flext itself is a programming interface to create a standard api between pd + max/msp, the library and its headers need to be installed in a known path and thus becomes a dependency to any library using flext. additionally it has optional simd sse/altivec optimizations, and can be extended further with sndobj and stk (synthesis tookit).
i guess for a start it would be ok to leave out SIMD as well as sndobj and STK, although it should definitely be includable later on. Compilation of the flext library is really straightforward. The few preprocessor defs should not really require autoconf.
Also, when flext availability within pd-ext is given, most of the flext-based externals can be built with fixed path settings for the flext headers and libraries (not requiring autoconf either). py/pyext and others are notable exceptions, though.
the current flext buildsys compiles the libs reliant on flext from a single build script, using definitions set in each libs src folder (package.txt), thus each lib is aware of the environment settings that flext was compiled with and some libs (eg. py/ext) require the user to manipulate an additional configuration file to define other system settings.
i concede that it may be possible to make some libs easily conform to the makefile template, but then the pd template is rather useless for building the same lib for max/msp, which if i recall is a popular reason for using flext in the first place.
Maybe it's ok to ignore Max for all autobuild-related questions, because the trusty flext build system can still be used for that.
gr~~~