Update of nvidia-304 not possible on kernel 4.15.0-46

[^rooker]

After updating to kernel image 4.15.0-46, the proprietary Nvidia driver 304 module cannot be built anymore.

Graphics card is:
> 01:00.0 VGA compatible controller: NVIDIA Corporation GF119 [GeForce GT 520] (rev a1)

System is on Xubuntu 16.04.6, 64bit.
Nouveau driver works as fallback, but without hardware acceleration.
Currently testing nvidia-340. Seems fine, but thought I'd report this since booting a working dual-screen setup to single 800x600px after a regular upgrade may scare the hell out of regular users ;)

Here are the error messages during package install, when module compilation is triggered:

Loading new nvidia-304-304.135 DKMS files...
Building only for 4.15.0-46-generic
Building for architecture x86_64
Building initial module for 4.15.0-46-generic

ERROR: Cannot create report: [Errno 17] File exists: '/var/crash/nvidia-304.0.crash'
Error! Bad return status for module build on kernel: 4.15.0-46-generic (x86_64)
Consult /var/lib/dkms/nvidia-304/304.135/build/make.log for more information.

Processing triggers for libc-bin (2.23-0ubuntu11) ...
Processing triggers for initramfs-tools (0.122ubuntu8.14) ...
update-initramfs: Generating /boot/initrd.img-4.15.0-46-generic

The mentioned logfile says:

DKMS make.log for nvidia-304-304.135 for kernel 4.15.0-46-generic (x86_64)
Mon 18 Mar 13:01:47 CET 2019
NVIDIA: calling KBUILD...
test -e include/generated/autoconf.h -a -e include/config/auto.conf || (^I^I\
echo >&2;^I^I^I^I^I^I^I\
echo >&2 " ERROR: Kernel configuration is invalid.";^I^I\
echo >&2 " include/generated/autoconf.h or include/config/auto.conf are missing.";\
echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it.";^I\
echo >&2 ;^I^I^I^I^I^I^I\
/bin/false)
mkdir -p /var/lib/dkms/nvidia-304/304.135/build/.tmp_versions ; rm -f /var/lib/dkms/nvidia-304/304.135/build/.tmp_versions/*
make -f ./scripts/Makefile.build obj=/var/lib/dkms/nvidia-304/304.135/build

Has the time come for 304 to phase out due to age?
Thanks in advance.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: nvidia-304 (not installed)
ProcVersionSignature: Ubuntu 4.15.0-46.49~16.04.1-generic 4.15.18
Uname: Linux 4.15.0-46-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
DKMSKernelVersion: 4.15.0-46-generic
Date: Mon Mar 18 12:59:28 2019
DuplicateSignature: dkms:nvidia-304:304.135-0ubuntu0.16.04.3:/var/lib/dkms/nvidia-304/304.135/build/nv.c:3033:5: error: implicit declaration of function ‘init_timer’ [-Werror=implicit-function-declaration]
InstallationDate: Installed on 2017-10-26 (507 days ago)
InstallationMedia: Xubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
PackageVersion: 304.135-0ubuntu0.16.04.3
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.5
 apt 1.2.29ubuntu0.1
SourcePackage: nvidia-graphics-drivers-304
Title: nvidia-304 304.135-0ubuntu0.16.04.3: nvidia-304 kernel module failed to build
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.modprobe.d.nvidia-304_hybrid.conf: [deleted]

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.