It looks like the patch at the following URL has either not made it into Qt 4.7.1 or it has somehow managed to get lost if it was previously part of Qt:

http://gitorious.com/+qtwebkit-developers/webkit/qtwebkit/commit/cbd47dc5626f6b1063e14736c69a8c23eccc1bf1

Note that the patch appears to be two years old, so it would seem long enough for it to have found its way into Qt by now. Without this patch, Qt's webkit module cannot be built with the linux-lsb-g++ mkspec against LSB 4.0, since pthread_getattr_np() has only been added as of the LSB 4.1 beta. Note that LSB 4.0 will be an important version to support for some time, since major linux distributions were only recently certified to 4.0. If recent history is anything to go by, it could be another year or two before we see them certify to 4.1, when it eventually comes out of beta.