Re: [C++ Patch] PR 88986 ("[7/8/9 Regression] ICE: tree check: expected tree that contains 'decl minimal' structure, have 'error_mark' in member_vec_binary_search, at cp/name-lookup.c:1136")

[Jason Merrill]

On 2/1/19 3:52 PM, Paolo Carlini wrote:
Hi,
I think that this ICE on invalid (and valid, for c++17+) can be in fact 
avoided by accepting in make_typename_type a TYPE_PACK_EXPANSION as 
context, thus by not triggering the "‘T ...’ is not a class" error. Not 
sure if a better fix would be something more general. Note, anyway, that 
we are asserting TYPE_P (context) thus TYPE_PACK_EXPANSIONs definitely 
get through beyond MAYBE_CLASS_TYPE_P.

The testcase should test that the using actually works, i.e. imports a 
type from a base class.

Jason