Gentoo's Bugzilla –
Attachment 582506 Details for
Bug 685346x11-drivers/nvidia-drivers-{390.116-r2410.104-r2,415.27-r2} with kernel 5.1.0 - In file included from .../work/kernel/nvidia/nv-instance.c:13: .../work/kernel/common/inc/nv-list-helpers.h:94:19: error: redefinition of ‘list_is_first’