segmentation fault on xawait

[Pismice]

When running this basic code I get a segmentation fault on the line where I xawait.

This is the code:

const libcoro = @import("libcoro");

fn myCoroutine(x: *usize) usize {
    x.* += 1;
    libcoro.xsuspend();
    x.* += 3;
    libcoro.xsuspend();
    return x.* + 20;
}

pub fn main() !void {
    const allocator = std.heap.page_allocator;
    const stack = try libcoro.stackAlloc(allocator, null);
    //    defer allocator.free(stack);

    var x: usize = 0;

    const frame = try libcoro.xasync(myCoroutine, .{&x}, stack);
    const res = libcoro.xawait(frame);

    std.debug.print("res: {}\n", .{res});
}

This is the backtrace:

 Segmentation fault at address 0x0
/home/tetratrux/.cache/zig/p/122058b315816dbabd2a812fb22d5670c4b3a4ca8e12ef3b6f02e48de66638e74ff9/src/coro.zig:612:13: 0x10796a4 in check (croco)
        if (magic_number_ptr.* != magic_number or //
            ^
/home/tetratrux/.cache/zig/p/122058b315816dbabd2a812fb22d5670c4b3a4ca8e12ef3b6f02e48de66638e74ff9/src/coro.zig:153:28: 0x1068bde in xsuspendSafe (croco)
    try StackOverflow.check(coro);
                           ^
/home/tetratrux/.cache/zig/p/122058b315816dbabd2a812fb22d5670c4b3a4ca8e12ef3b6f02e48de66638e74ff9/src/coro.zig:132:17: 0x103650b in xsuspend (croco)
    xsuspendSafe() catch |e| {
                ^
/home/tetratrux/.cache/zig/p/122058b315816dbabd2a812fb22d5670c4b3a4ca8e12ef3b6f02e48de66638e74ff9/src/coro.zig:77:39: 0x10338c2 in xawait__anon_2457 (croco)
    while (f.status != .Done) xsuspend();
                                      ^
/home/tetratrux/kDrive/A_HEIG/ZIG/croco/src/main.zig:20:31: 0x10337f8 in main (croco)
    const res = libcoro.xawait(frame);
                              ^
/home/tetratrux/.zvm/0.12.0/lib/std/start.zig:511:37: 0x1033e8e in main (croco)
            const result = root.main() catch |err| {

Any idea why this could happen ?