Ruby 1.9.2 and pcap gem? Compiling error

问题

I am having trouble installing the pcap gem with ruby 1.9.2... It works fine with 1.8.7. Anyone know whats going on?

wuntee@wuntee:~$ rvm use system
Now using system ruby.
wuntee@wuntee:~$ ruby -v
ruby 1.8.7 (2009-06-12 patchlevel 174) [universal-darwin10.0]
wuntee@wuntee:~$ gem install pcap
WARNING:  Installing to ~/.gem since /Library/Ruby/Gems/1.8 and
      /usr/bin aren't both writable.
WARNING:  You don't have /Users/wuntee/.gem/ruby/1.8/bin in your PATH,
      gem executables will not run.
Building native extensions.  This could take a while...
Successfully installed pcap-0.7.0
1 gem installed
Installing ri documentation for pcap-0.7.0...
Installing RDoc documentation for pcap-0.7.0...
wuntee@wuntee:~$ rvm use 1.9.2
Using /Users/wuntee/.rvm/gems/ruby-1.9.2-p180
wuntee@wuntee:~$ ruby -v
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-darwin10.6.0]
wuntee@wuntee:~$ gem install pcap
Building native extensions.  This could take a while...
ERROR:  Error installing pcap:
    ERROR: Failed to build gem native extension.

        /Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/bin/ruby extconf.rb
checking for socket() in -lsocket... no
checking for gethostbyname() in -lxnet... no
checking for hstrerror()... yes
checking for pcap.h... yes
checking for pcap_open_live() in -lpcap... yes
checking for pcap_compile_nopcap()... yes
creating Makefile

make
gcc -I. -I/Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/x86_64-darwin10.6.0 -I/Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/backward -I/Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1 -I. -DHAVE_HSTRERROR -DHAVE_PCAP_H -DHAVE_PCAP_COMPILE_NOPCAP -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE   -fno-common -I/usr/local/include  -o icmp_packet.o -c icmp_packet.c
gcc -I. -I/Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/x86_64-darwin10.6.0 -I/Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1/ruby/backward -I/Users/wuntee/.rvm/rubies/ruby-1.9.2-p180/include/ruby-1.9.1 -I. -DHAVE_HSTRERROR -DHAVE_PCAP_H -DHAVE_PCAP_COMPILE_NOPCAP -D_XOPEN_SOURCE -D_DARWIN_C_SOURCE   -fno-common -I/usr/local/include  -o ip_packet.o -c ip_packet.c
ip_packet.c: In function ‘ipp_set_src’:
ip_packet.c:117: error: ‘struct RString’ has no member named ‘ptr’
ip_packet.c: In function ‘ipp_set_dst’:
ip_packet.c:118: error: ‘struct RString’ has no member named ‘ptr’
ip_packet.c: In function ‘new_ipaddr’:
ip_packet.c:186: warning: cast to pointer from integer of different size
ip_packet.c: In function ‘ipaddr_s_new’:
ip_packet.c:203: error: ‘struct RString’ has no member named ‘ptr’
ip_packet.c:213: warning: format not a string literal and no format arguments
ip_packet.c: In function ‘ipaddr_s_load’:
ip_packet.c:320: error: ‘struct RString’ has no member named ‘len’
ip_packet.c:324: error: ‘struct RString’ has no member named ‘ptr’
make: *** [ip_packet.o] Error 1


Gem files will remain installed in /Users/wuntee/.rvm/gems/ruby-1.9.2-p180/gems/pcap-0.7.0 for inspection.
Results logged to /Users/wuntee/.rvm/gems/ruby-1.9.2-p180/gems/pcap-0.7.0/ext/gem_make.out
wuntee@wuntee:~$

回答1:

Two easy find and replace steps...

Replace RSTRING(foo)->ptr with RSTRING_PTR(foo).

Replace RSTRING)foo)->len with RSTRING_LEN(foo).

Seems like you can ignore the warnings for now, although it might break in a newer version of ruby.

Edit: getting it to actually WORK is a different story. I spent the better part of the weekend tracing this down into the ruby-c extension itself and some bogus calls to trap any interrupts and block forever. Based on how I understand this working on OS X, additional blocking shouldn't be required. Hopefully this will pulled into the gem soon, but in the meantime you can get the working version from this github account here