looked like:
./configure: line 6651: syntax error near unexpected token `in'
./configure: line 6651: ` for ac_header in'
configure: error: ./configure failed for libpcap
Example: http://seclists.org/nmap-dev/2010/q1/444
The problem is a bogus empty test in the libpcap/configure.in. It
was actually fixed by libpcap in SVN back in 2008, but there hasn't
been a release since then :(. They seem to still be actively developing,
just not making releases. Sigh.