zcc with sdcc fails frequently on msys2

[pauloscustodio]

The test code:

char f(char a) {
        return (a >> 4);
}
int main() {
        return f(0x12);
}

compiled with zcc +zxn -v --list -o test_t_issue_1874.dir/test test_t_issue_1874.dir/test.c fails silently about half of the runs on msys2. I've added a perror() at zcc.c:1414 and the error output is "No such file or directory".

My guess is that the input file to sdcc is not ready yet when the sdcc process starts.