Ports extracting on old freebsd (7.2 my), xz inappropriate file type or format

Before starting compiling libarchive, i put spawn.h to /usr/include, because in my system it doesn't existed.

CC     libarchive/filter_fork_posix.lo
libarchive/filter_fork_posix.c:61:21: error: spawn.h: No such file or directory
*** Error code 1

Stop in /usr/ports/archivers/libarchive/work/libarchive-3.1.2.
*** Error code 1

# cd /usr/include/
# wget https://gist.github.com/OmIkRoNiXz/5625492/raw/71b8edba74636f513a0e301a2da12caa2d68f417/spawn.h

Now i can install libarchive.

# cd /usr/ports/archivers/libarchive 
# make install clean

# ln -sf /usr/local/bin/bsdtar /usr/bin/tar

And it all!