From Salix OS
The kernel-source package is by default locked in gslapt, just like all other kernel related packages. This is to prevent users from unknowingly upgrading the kernel; it's easy to miss that kernel packages are about to be upgraded, when a multitude of other packages are going to be upgraded at the same time.
In order to install the kernel-source package, open a terminal window, run
and provide your root password to become root. Update your package database (just to be sure):
and request to install the kernel-source package explicitly with slapt-get:
slapt-get -i kernel-source
That's it, the kernel-source package should be downloaded and installed when the download is finished.