These appear not to have any effect any more. They were initially used
to conditionally compile and link some files with replacements for
standard library functions, but seem not to have been used after r828
("Moved to nbase system for compatability funcs").
John Spencer reported that musl libc doesn't automatically include
<stdlib.h>, as Glibc does, so the configure check was wrongly failing.
conftest.c: In function 'main':
conftest.c:35:5: error: implicit declaration of function 'exit'
The lack of this was causing PCAP_IS_SUITABLE to fail on Arch Linux, at
least. I think that in some cases this caused both -L../libpcap and
-lpcap to be added to the linker line, which could cause an error
because of the need to link with -lnl. (We check for -lnl when
--with-libpcap=included is used (since r23163), but the PCAP_IS_SUITABLE
failure went around this check and allowed linking with the included
libpcap without checking whether -lnl is required.)
Here are reported build failures and responses:
http://seclists.org/nmap-dev/2011/q3/449http://seclists.org/nmap-dev/2011/q4/33http://seclists.org/nmap-dev/2012/q1/369
If you have trouble updating after this revision you need to follow
these instructions. You have probably just seen an error like this:
svn: URL 'svn://svn.insecure.org/nping' of existing directory 'nping'
does not match expected URL 'svn://svn.insecure.org/nmap/nping'
This is caused by the replacement of SVN externals.
Here's what you need to do. First, save any local changes you might have
in the nping, nsock, nbase, ncat, and zenmap directories. (For example
by running "cd nping; svn diff > ../nping.diff".) If you don't have any
local changes you can skip this step.
Then run these commands:
rm -rf nping/ nsock/ nbase/ ncat/ zenmap/
svn update
svn cleanup
If all else fails, you can just delete your whole working directory and
check out anew:
svn co --username guest --password "" svn://svn.insecure.org/nmap
There may be further discussion in the mailing list thread at
http://seclists.org/nmap-dev/2011/q4/303.
