Build error on 5.3.0-19-generic; dkms says module installed fine

Error reported during build, but dkms reports successful build.

Dkms build appears to complete successfully despite error reports, so maybe only a cosmetic error during the build process?

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: nvidia-340 340.107-0ubuntu7
ProcVersionSignature: Ubuntu 5.3.0-18.19-generic 5.3.1
Uname: Linux 5.3.0-18-generic x86_64
NonfreeKernelModules: nvidia zfs zunicode zavl icp zcommon znvpair wl
ApportVersion: 2.20.11-0ubuntu8
Architecture: amd64
Date: Tue Oct 22 09:47:38 2019
InstallationDate: Installed on 2019-10-11 (10 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Beta amd64 (20191010)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: nvidia-graphics-drivers-340
UpgradeStatus: No upgrade log present (probably fresh install)