FreeBSD 6.2 and OpenBSD 4.0 ./configure "issues"

checking tiffio.h usability... yes
checking tiffio.h presence... no
configure: WARNING: tiffio.h: accepted by the compiler, rejected by the preproce                            ssor!
configure: WARNING: tiffio.h: proceeding with the compiler's result
checking for tiffio.h... yes


checking spandsp.h usability... yes
checking spandsp.h presence... no
configure: WARNING: spandsp.h: accepted by the compiler, rejected by the preproc                            essor!
configure: WARNING: spandsp.h: proceeding with the compiler's result
checking for spandsp.h... yes


### this is FreeBSD only ###
checking popt.h usability... yes
checking popt.h presence... no
configure: WARNING: popt.h: accepted by the compiler, rejected by the preprocess                            or!
configure: WARNING: popt.h: proceeding with the compiler's result
checking for popt.h... yes


BUILD_MACHINE:  
BUILD_HOST:     
SVN:            echo Missing subversion so some stuff will be borked
SVN_VERSION:


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# Questions

- Why do I get those warnings from the preprocesser?
- Why is subversion needed?
- Will subversion also be a dependency for the release version?
- Why are the VARs about the machine empty?