Ben Hutchings writes ("Detecting install vs upgrade in postinst"):
> The postinst script for linux-image-* behaves differently on fresh
> installation vs upgrade. For a fresh installation, it updates the
> default symlinks /vmlinuz and /initrd.img to point to the new kernel
> and initramfs versions. On upgrade it generally doesn't.
By the time of the postinst, dpkg no longer has the record of whether
the unpack was a fresh install, reinstall, or upgrade. You might be
able to provide a preinst or prerm which would capture or act on its
arguments, which differ for upgrades.
I'm not sure of the rationale behind the behaviour you describe. So
I'm not really happy trying to invent for you a specific scheme. But
hopefully you can do that.
Note that the preinst (and postrm) do not have the package's
dependencies available.
> Is there a simple way that a postinst script can tell that the
> previously configured version was removed? Or do I have to use some
> sort of flag file? (I can imagine either creating this in the preinst,
> or creating it in postinst and removing it in postrm.)
As I say, I'm not sure why it's relevant that the
previously-configured version was removed.
Ian.
