The following shader fails to compile:

        @id(1001) override c1: u32;            // some big numeric id
        @id(1) override c2: u32 = 0u;          // id == 1 might collide with some generated constant id
        @id(1003) override c3: u32 = 3u;       // default

        struct Buf {
            data : array<u32, 3>
        }

        @group(0) @binding(0) var<storage, read_write> buf : Buf;

        @compute @workgroup_size(1) fn main() {
            buf.data[0] = c1;
            buf.data[1] = c2;
            buf.data[2] = c3;

2:8: Unknown attribute. Supported attributes are 'group', 'binding', 'location', 'builtin', 'vertex', 'compute', 'fragment'.