Does a man who is in debt have to do Hajj when someone else is paying for it?

 Shaykh Muhammad ibn ‘Uthaymeen
(may Allaah have mercy on him) was asked this question and he said

 If this brother wants
to pay your expenses for Hajj, so that going with him will not cost
you anything, then it is OK for you to go on Hajj with him, but you
do not have to go for Hajj with him. The reason why we say that it is
not obligatory is because this brother is doing you a favour, and there
is the fear that some day he may no longer be a brother in Islam to
you [i.e., problems may arise between you and you may no longer be close],
then he may remind you of his favour and say, “This is what I get for
having taken you on Hajj with me in such-and-such a year, and now you
have done this to me…!”