Interesting, never heard of this make feature before. Does that only work with static libs? Because the .so is in the search path.
It's supposed to work with both static and shared libs. The defaults for skarnet.org package installations specify *different* directories for static libraries and shared libraries. It is a misdesign of autotools, or other build systems, to ensure that those installation directories are the same: static and shared libraries are very different objects and should not be handled the same way or stored at the same place. (Shared libraries are a run-time object; static libraries are a compile-time object, only used for development.)
Or is it the case that ld/gcc understand LIBRARY_PATH but make doesn't?
Yes. CPATH and LIBRARY_PATH are gcc-specific constructs. The equivalent of LIBRARY_PATH for make is named "vpath", and needs to be declared in the Makefile. The configure script builds such a vpath with the contents of the given --with-lib options.
"--enable-fast-install"
The configure scripts are not generated by autotools. This flag won't do anything. Please see ./configure --help to see what flags are supported.
skalibs lib and includes are found using CPATH and LIBRARY_PATH.
Yeah, that will work with gcc but make will not find libraries. As you could see for yourself, it works with --with-lib. :) -- Laurent
