r8168-dkms 8.037.00-1: r8168 kernel module failed to build [error: implicit declaration of function ‘vlan_tx_tag_present’]

[Reinhard Katzmann]

WHen building kernel 4.2.0-36 dkms fails to build (​#1487605)
This issue also exist on Ubuntu 15.04 (8.0.39) but the version from LTS 14.04 is r8168-8.037.00-1.

A patch for the issue is available that can be easily applied to fix the issue.

This is a severe issue as it breaks networking on my Notebook using this kernel. Older kernel version of 4.2.0 did not break the build.

 DKMS make.log for r8168-8.037.00 for kernel 4.2.0-36-generic (x86_64)
 Do 2. Jun 08:13:21 CEST 2016
 make: Verzeichnis »/usr/src/linux-headers-4.2.0-36-generic« wird betreten
   LD /var/lib/dkms/r8168/8.037.00/build/built-in.o
   CC [M] /var/lib/dkms/r8168/8.037.00/build/r8168_n.o
 /var/lib/dkms/r8168/8.037.00/build/r8168_n.c: In function ‘rtl8168_tx_vlan_tag’:
 /var/lib/dkms/r8168/8.037.00/build/r8168_n.c:2705:12: error: implicit declaration of function ‘vlan_tx_tag_present’ [-Werror=implicit-function-declaration]
      tag = (vlan_tx_tag_present(skb)) ?
             ^

ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: r8168-dkms 8.037.00-1
ProcVersionSignature: Ubuntu 3.13.0-86.131-generic 3.13.11-ckt39
Uname: Linux 3.13.0-86-generic x86_64
NonfreeKernelModules: wl fglrx
ApportVersion: 2.14.1-0ubuntu3.21
Architecture: amd64
DKMSKernelVersion: 4.2.0-36-generic
Date: Thu Jun 2 08:13:49 2016
DuplicateSignature: dkms:r8168-dkms:8.037.00-1:/var/lib/dkms/r8168/8.037.00/build/r8168_n.c:2705:12: error: implicit declaration of function ‘vlan_tx_tag_present’ [-Werror=implicit-function-declaration]
InstallationDate: Installed on 2014-06-08 (724 days ago)
InstallationMedia: Ubuntu-Studio 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.3)
PackageArchitecture: all
PackageVersion: 8.037.00-1
RelatedPackageVersions:
 dpkg 1.17.5ubuntu5.6
 apt 1.0.1ubuntu2.14
SourcePackage: r8168
Title: r8168-dkms 8.037.00-1: r8168 kernel module failed to build
UpgradeStatus: No upgrade log present (probably fresh install)

[Reinhard Katzmann (suamor)]

I meant to say that the issue number from 15.04 is #1487605.