Good afternoon, I observe a very strange behavior: the following code segfaults. Looks like resource limit kicks in (because huge_tree=True solves the problem). But there is a strange thing: commenting out etree.fromstring() solves the problem. Is this a bug? BTW, creating a new parser in the loop does not help. May be parser should be closed/deinitialized somehow? Here is the code (mirror: http://dpaste.com/13G071K): #!/usr/bin/env python from lxml import etree import string import random def id_generator(size=6, chars=string.ascii_uppercase + string.digits): return ''.join(random.choice(chars) for _ in range(size)) parser= etree.XMLParser( # huge_tree=True ) # Bug? Without it all works fine etree.fromstring('<x></x>', parser=parser) tag = etree.QName('tag') value = etree.QName('id') for i in range(1, 1_000_000): # this doesn't help at all, parsers share resource counters? parser = etree.XMLParser() x = parser.makeelement(tag) rand_id = id_generator() x.set(f"x_{rand_id*100}", value) for c in x.iter(): c.attrib.items() -- Kind Regards, Alexandre