Comptime segfault on recursive types

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I’m starting to think that’s what’s going on here. In godbolt, I can remove the logic of your branches and just see what branches we’re getting into for your minimal example:

const std = @import("std");

fn traverse(comptime val: anytype) void {
    const T = @TypeOf(val);
    switch (@typeInfo(T)) {
        .Union => {
            if (@typeInfo(T).Union.tag_type) |Tag| {
                switch (@as(Tag, val)) {
                    inline else => |tag| {
                        traverse(@field(val, @tagName(tag)));
                    },
                }
            }
        },
        .Pointer => {
            @compileError("In pointer branch");
        },
        .Int => {
            @compileLog("In integer branch");
        },
        else => {}
    }
}

For the following code, we hit the integer branch only:

pub fn main() !void {
    const Union = union(enum) {
        int: u8,
        self: *const @This(),
    };
    const val = Union{ .int = 10 };
    comptime traverse(val);
}
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