You receive this bug because this package does not respect my system's CC ( x86_64-pc-linux-gnu-gcc - /usr/bin/x86_64-pc-linux-gnu-gcc ) and calls directly gcc -/usr/bin/gcc The possible solutions to fix this issue are: 1)Fix the buildsystem, if you can 2)inherit toolchain-funcs and use tc-export CC 3)inherit toolchain-funcs and use emake CC="$(tc-getCC)" cc -march=native -O2 -g0 -pipe -Wall -Wmissing-prototypes -Wstrict-prototypes -Wpointer-arith -Wunused -DVERSION="2.09" -I. -Wno-pointer-sign -Ijpeg/80 -DHAVE_ENDIAN_H -DHAVE_STRCASESTR -DHAVE_NEW_EXIF -DHAVE_LIBWEBP -Wp,-MD,mk/exiftran.tmp -c -o exiftran.o exiftran.c