Mucormycosis in cancer patients - an emerging threat

The incidence of ‘black fungus’ has increased manifold during the ‘second wave’ of covid-19. There is a lot of panic and anti-fungals are in high demand and not easily available currently. So what exactly is this ‘black fungus’? Is it a novel infection like the Covid -19? Does it affect only covid patients or even others are at risk? How deadly is it?