dustmite minimized example (probably could be minimized a bit further): ``` template AllMembersInModule(alias Module) { import std: AliasSeq, Filter; alias all_members = AliasSeq!(__traits(allMembers, Module)); template CanAccess(string member) { enum CanAccess = __traits(compiles, __traits(getMember, Module, member)); } alias x = Filter!(CanAccess, all_members); alias AllMembersInModule = y; } template t() { alias MODULE = __traits(parent, {}); static foreach (M; AllMembersInModule!MODULE) { } } alias AllMembers = AllMembersInModule!(__traits(parent, {})); mixin t; ``` The issue here is a typo: `y` should be `x`, but we get an unknown error instead. If I remove `alias AllMembers` it works as expected. BTW, if I remove `mixin t` line, it compiles without error, is it expected, are aliases lazy?
I couldn't reduce it any more than this: ``` template AllMembersInModule(alias Module) { import std.meta : Filter; alias all_members = __traits(allMembers, Module); template CanAccess(string member) { enum CanAccess = __traits(compiles, __traits(getMember, Module, member)); } alias x = Filter!(CanAccess, all_members); alias AllMembersInModule = y; } alias AllMembers = AllMembersInModule!(__traits(parent, {})); pragma(msg, AllMembers); // added ``` Error: unknown, please file report on issues.dlang.org aliastypo.d(15): while evaluating `pragma(msg, AllMembers)`