This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 109b. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
The current grammar does not allow indicating that a lambda is noreturn, because currently attributes in a lambda-expression appertain to the type of the conversion function/template, per 7.5.5 [expr.prim.lambda] paragraph 5.
Additional note (February, 2022):
This issue was addressed by the adoption of paper P2173R1 at the February, 2022 plenary.