Gentoo's Bugzilla –
Attachment 770885 Details for
Bug 838469app-emulation/fs-uae-3.1.66 - src/memory.cpp: In function 'bool mapped_malloc(addrbank*)': src/memory.cpp:1875:32: error: converting to 'bool' from 'std::nullptr_t' requires direct-initialization [-fpermissive] (on musl)