After upgrading to Snow Leopard, I found that installing some gems no longer worked, including webrat, mechanize etc. Each time I get this error:
checking f
UPDATE
As stated in another answer, the below solution is 'overkill' because it removes MacPorts from your system, which I thought I had already done earlier. Proceed carefully. There may be a way to use MacPorts to just update the libxml2 install.
I solved this problem (on my machine at least).
Once I realized that nothing in that trace suggested the lack of libxml2, but rather a problem with the version being detected, I looked around for confirmation of this fact. Sure enough, the nokogiri website (where many similar bug reports pointed me) states in no uncertain terms that Snow Leopard ships with a good working version of libxml2.
Thus, I reasoned that I must have installed a version by another means long ago. I would remember if I had installed by hand, so there was really only one option left, frickin' macports.
$ libxml2-2.7.1 tfwright$ sudo find / -type d -name "libxml2"
find: /dev/fd/3: Not a directory
find: /dev/fd/4: Not a directory
/Developer/SDKs/MacOSX10.4u.sdk/usr/include/libxml2
/Developer/SDKs/MacOSX10.5.sdk/usr/include/libxml2
/Developer/SDKs/MacOSX10.6.sdk/usr/include/libxml2
/opt/local/include/libxml2
/opt/local/share/gtk-doc/html/libxml2
/opt/local/var/macports/distfiles/libxml2
/opt/local/var/macports/receipts/libxml2
/opt/local/var/macports/software/libxml2
/opt/local/var/macports/software/libxml2/2.6.30_0/opt/local/include/libxml2
/opt/local/var/macports/software/libxml2/2.6.30_0/opt/local/share/gtk-doc/html/libxml2
/opt/local/var/macports/sources/rsync.macports.org/release/ports/textproc/libxml2
/usr/include/libxml2
/usr/share/gtk-doc/html/libxml2
Son of a...just blowing away /opt/local/var/macports
, which I tried first of all, didn't seem to fix the problem, so I went to the big guns.
sudo rm -rf \
/opt/local \
/Applications/DarwinPorts \
/Applications/MacPorts \
/Library/LaunchDaemons/org.macports.* \
/Library/Receipts/DarwinPorts*.pkg \
/Library/Receipts/MacPorts*.pkg \
/Library/StartupItems/DarwinPortsStartup \
/Library/Tcl/darwinports1.0 \
/Library/Tcl/macports1.0 \
~/.macports
After which, everything installs fine. that's right. Never trust the recommendations of error messages! Far from needing to reinstall libxml2 with macports, I needed to scrub away all traces of macports from my system, which was haunting me from beyond the trash.