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'LICENSE' is not a known MakeMaker parameter name.
Note (probably harmless): No library found for -lRmath
Writing Makefile for Math::GammaFunction
cp lib/Math/GammaFunction.pm blib/lib/Math/GammaFunction.pm
/home/cpanrun/build/5.6.1/bin/perl -I/home/cpanrun/build/5.6.1/lib/5.6.1/i686-linux-thread-multi -I/home/cpanrun/build/5.6.1/lib/5.6.1 /home/cpanrun/build/5.6.1/lib/5.6.1/ExtUtils/xsubpp  -typemap /home/cpanrun/build/5.6.1/lib/5.6.1/ExtUtils/typemap GammaFunction.xs > GammaFunction.xsc && mv GammaFunction.xsc GammaFunction.c
Please specify prototyping behavior for GammaFunction.xs (see perlxs manual)
gcc -c -I. -DUSE_REENTRANT_API -D_GNU_SOURCE -D_REENTRANT -fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2   -DVERSION=\"0.02\" -DXS_VERSION=\"0.02\" -fpic -I/home/cpanrun/build/5.6.1/lib/5.6.1/i686-linux-thread-multi/CORE  GammaFunction.c
GammaFunction.xs:8: Rmath.h: No such file or directory
make: *** [GammaFunction.o] Error 1