Low-level Error: Overlapping input varnodes

[brainstorm]

I'm reversing this STM8S003 firmware (flash.bin file):

https://github.com/brainstorm/treadmill-re/tree/master/control

The decompilation seems to fail (offset 0x8ee9)... any ideas on what might be causing this error?:

According to similar issues, there seems to be some register conflict so perhaps there's some flaw in the sleigh definition? ... oh, I just found I reported it last year (totally forgot): NationalSecurityAgency/ghidra#3602 (comment)

Anyway, it seems to work with radare2's r2ai decompilation for now:

int fcn_00008ee9(int x, int y) {
    uint16_t sp[10];
    uint8_t a, xl, yl;
    uint16_t res;

    fcn_00008c70();
    fcn_00008e06();

    if (x >= 0x01f4) {
        x = 0x03e8;
    }

    while (x < 0x018b) {
        x++;
    }

    while (x > 0x0640) {
        x -= sp[9];
    }

    for (int i = 0; i < 5; i++) {
        fcn_00009e24();
        fcn_00009e07();
    }

    fcn_00009cbf();
    fcn_00009cd1();
    fcn_00009bf7();
    fcn_00009ba8();

    *(uint8_t*)PORTA_DDR |= (1 << 1);
    *(uint8_t*)PORTA |= (1 << 1);
    *(uint8_t*)PORTA &= ~(1 << 2);

    for (int i = 0; i < 3; i++) {
        fcn_00009e24();
        fcn_00009e07();
        fcn_00009cbf();
        fcn_00009cd1();
    }

    fcn_00009bc8();
    fcn_00009bef();

    *(uint8_t*)PORTA |= (1 << 3);
(...)