Comment 6 for bug 1608753

When examining repos it seems like the inconsistency was introduced in xenial-updates where packages in the build toolchain was bumped from 5.3.1 to 5.4.0 while the supplied kernel still is built with GCC 5.3.1 and the dependecy-packages that provide symlinks to tool-binaries also remain at version 5.3.1

Package xenial xenial-security xenial-updates
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gcc 4:5.3.1-1ubuntu1
gcc-5 5.3.1-14ubuntu2 5.3.1-14ubuntu2.1 5.4.0-6ubuntu1~16.04.1

The issue of inconsistent versions relates to a number of packages in the chain of build-tools (binaries and libraries) tagged with versions 5.3.1 and/or 5.4.0. DKMS is not to blame.