External Source kernel modules install does not fail as it should

Another small post to serve for future memory that when you are building Linux Kernel modules from external tree source, the kernel build system behaves differently. Yesterday it happened that I lost a huge amount of time trying to understand why the installation of a module was not exiting with error, when I clearly saw errors in the logs. The reason is that this is on purpose. In the build scripts for kernel installation there is this hidden gem: https://github.com/torvalds/linux/commit/f6a79af8f3701b5a0df431a76adee212616154dc Don't stop modules_install if we can't sign external modules. I have been warned.