  Up-to-date, there is no known example of a classical de Sitter solution of
string theory, despite several good candidates. We consider here two newly
discovered 10d supergravity de Sitter solutions, and analyse in great detail
whether they can be promoted to classical string backgrounds. To that end, we
identify five requirements to be met, and develop the necessary 10d tools to
test the solutions. Eventually, they both fail to verify simultaneously all
requirements, in spite of positive partial results. The explicit values
obtained offer a clear illustration of the situation, and the analysis
highlights various subtleties. We finally discuss the relation to the problem
of scale separation.
