I can confirm that the alignment is wrong. To prove, I created this repo: https://github.com/FROGGS/p6-Gumbo Running `perl6 t` gives: ~/dev/gumbo$ perl6 t/00-structure-sizes.t 1..19 ok 1 - sizeof(size_t) ok 2 - sizeof(GumboStringPiece) ok 3 - sizeof(GumboSourcePosition) ok 4 - sizeof(GumboVector) ok 5 - sizeof(GumboTag) ok 6 - sizeof(GumboNamespaceEnum) ok 7 - sizeof(MyGumboTest) not ok 8 - sizeof(GumboElement)
# Failed test 'sizeof(GumboElement)' # at t/00-structure-sizes.t line 85 # expected: '96' # got: '104' Which hints at the last two attributes of the GumboElement structure, as the ticket already pointed out.
