Unable to use FlecsRest

[jarednorman]

Not sure if this is related to #2, but struggling to get to EcsRest to work.

fatal: flecs.c: 9695: assert: entity != 0 INVALID_PARAMETER
1   7drl-2025                           0x000000010324f16c flecs_log_msg + 1512
2   7drl-2025                           0x0000000103270340 ecs_printv_ + 200
3   7drl-2025                           0x000000010322b744 ecs_log_ + 112
4   7drl-2025                           0x0000000103221574 ecs_assert_log_ + 272
5   7drl-2025                           0x000000010322e620 ecs_is_alive + 184
6   7drl-2025                           0x0000000103236db0 ecs_set_id + 180
7   7drl-2025                           0x00000001033478f0 zflecs.set__anon_6439 + 84
8   7drl-2025                           0x0000000103335ebc zflecs.singleton_set__anon_3370 + 52
9   7drl-2025                           0x0000000103333ee4 ecs.init + 116
10  7drl-2025                           0x000000010333396c main.main + 268
11  7drl-2025                           0x0000000103334260 main + 596
12  dyld                                0x000000018dc03154 start + 2476

[jarednorman]

More info:

Here's the code that triggers the issue:

ecs.FlecsRestImport(world);
std.debug.print("{d}\n", .{ecs.id(ecs.EcsRest)});
_ = ecs.singleton_set(world, ecs.EcsRest, .{});

It's worth noting that the print statement returns 0, which suggests to me that the call to FlecsRestImport is not doing the right thing.

[jarednorman]

For context, here's an issue from the monorepo on using this functionality: zig-gamedev/zig-gamedev#408

[Srekel]

Interesting, it seems the zflecs wrapper does something different than what we use on Tides. Will try to look into this during the weekend. In the meantime you may want to try this approach and see if that works.

https://github.com/Srekel/tides-of-revival/blob/e863528ebf8bc6324c11849087ae86a2220ed0c1/src/flecs_util/world.zig#L327

[Srekel]

Hi sorry, I've been on a bit of a break. I wonder if this may be easier now with the module PR I just merged in?

[woshiwuja]

Hi sorry, I've been on a bit of a break. I wonder if this may be easier now with the module PR I just merged in?

Do you have an example? Im having the same problem with the latest version.
If i dont create the rest component flecs fails with fatal: flecs.c: 8730: assert: entity != 0 INVALID_PARAMETER

pub fn main() !void {
    const world = ecs.init();
    defer _ = ecs.fini(world);
    ecs.FlecsRestImport(world);
    const e = ecs.singleton_set(world, ecs.EcsRest, .{});
    std.debug.print("ENTITY ID {}\n", .{e});
    while (true) {
        _ = ecs.progress(world, 0);
    }
}

Id never gets printed.

if i create the component beforehand:

pub fn main() !void {
    const world = ecs.init();
    defer _ = ecs.fini(world);
    ecs.COMPONENT(world, ecs.EcsRest);
    ecs.FlecsRestImport(world);
    const e = ecs.singleton_set(world, ecs.EcsRest, .{});
    std.debug.print("ENTITY ID {}\n", .{e});
    while (true) {
        _ = ecs.progress(world, 0);
    }
}

Then i get ENTITY ID 11810544449458039040, but the rest server is still unreachable

[woshiwuja]

This seems to work: (pulled from this zig-gamedev/zig-gamedev#408)

FlecsMonitorImport had to be deleted since it was not found

pub fn main() !void {
    const world = ecs.init();
    defer _ = ecs.fini(world);
    const EcsRest = ecs.lookup_fullpath(world, "flecs.rest.Rest");
    const EcsRestVal: ecs.EcsRest = .{};
    _ = ecs.set_id(world, EcsRest, EcsRest, @sizeOf(ecs.EcsRest), &EcsRestVal);
    while (true) {
        _ = ecs.progress(world, 0);
    }
}

[Srekel]

This is how I do it and have confirmed it works with the latest zflecs :)

https://github.com/Srekel/tides-of-revival/blob/main/src%2Fgame.zig#L304

Did you get it to work?

[woshiwuja]

Yup seems to work fine, got any idea why singleton_set doesnt seem to work?

[Srekel]

No, I'm not that familiar with modules yet. We do use singletons though (in Tides), look for EnvironmentInfo somewhere in there to see how.