Summary
In the execute_bip_119 pseudocode, the hash comparison references stack[-1] instead of self.stack[-1], inconsistent with all other stack references in the function:
# Correct:
if len(self.stack) < 1:
if len(self.stack[-1]) == 32:
# Incorrect — missing self.:
if stack[-1] != self.context.tx.get_default_check_template_hash(...)
In Python, stack[-1] would reference an undefined local variable, while self.stack[-1] correctly accesses the interpreter's stack. The C++ reference implementation uses stack.back() consistently and is not affected.
