Hi, I just tried installing lxml from git master, but Cython fails with hundreds of errors like these: src/lxml/iterparse.pxi:123:33: 'xmlDoc' is not a type identifier src/lxml/schematron.pxi:166:53: Constructing Python tuple not allowed without gil I’m running Cython 0.15.1 and CPython 2.7.2 and 3.2.2 (same result with both.), and installing (while in the git checkout directory) with pip install -e . I could kind of make it work by taking the *.c and *.h files from the latest release. This is good enough for me to work on cssselect, but running the whole test suite segfaults at test_html_prefix_nsmap (lxml.tests.test_etree.ETreeOnlyTestCase) (I’m not surprised by this segfault. The real problem is Cython errors above.) Regards, -- Simon Sapin