Hello Craig, Many thanks, I am learning, but whether I can remember, especially as not doing this sort of thing except infrequently, is another matter. I do want to learn, and remember, but some of the detail is slipping. On 2/16/19, Craig Sanders via luv-main <luv-main@luv.asn.au> wrote:
On Sat, Feb 16, 2019 at 03:01:35PM +1100, Mark Trickett wrote:
So I have two packages to update, plus any dependencies of libc6 of the later version. Now to learn how to find out what that might be. And then to see where that leads. Then to install the sane-utils (v 1.0.27) package. The capacity to manage and do this is why I am using Debian, but still not sufficiently familiar with all of it. I learn by doing, but have not done enough of it to know and remember, yet.
I have no idea what version of libc6 you have installed (the last stable release was ages ago, and i run sid aka unstable anyway) but if you have to upgrade libc6 to install the new sane packages, then that will trigger an enormous cascade of other upgrades, likely to result in a lot of breakage.
Require libc6 (>= 2.15), installed is 2.24-11+deb9u3. Think I was having a brain fart, looks like might not need to upgrade that. As to running sid, how stable do you find it, and how much effort to "unbreak" it when an update does break it?
To put it mildly, this is more trouble than it's worth.
It would be easier to just upgrade to 'sid' or 'testing'. Or compile backports for the SANE packages yourself.
I am seriously looking at that, scratching my head and getting splinters.
To install packages from sid or testing with apt, edit your sources.list file (either /etc/apt/sources.list or a file under /etc/apt/sources.list.d) and copy the line that lists "stable". change the copy to "testing" or "unstable".
BTW, you can do a partial upgrade to either sid or testing by:
1. adding entries for either (or both) of them to your sources.list. e.g.
deb http://your.nearest.debian.mirror/debian/ stable main non-free contrib deb http://your.nearest.debian.mirror/debian/ testing main non-free contrib deb http://your.nearest.debian.mirror/debian/ unstable main non-free contrib
2. and then adding the following to /etc/apt/apt.conf (or to a file under /etc/apt/apt.conf.d):
APT::Default-Release "stable";
That makes packages from sid or testing available, but they will NOT be installed unless you explicitly tell apt to install them with the '-t' (aka '--target-release') option. e.g.
apt-get update apt-get -V -d -u -t unstable install sane-utils libsane
That will verbosely show which packages *would* be upgraded and download them.
Verify that the command won't do anything unexpected (like removing other packages - such as your desktop environment - or upgrading 1000 other packages) and then run the same command without the "-V" or "-d" options to actually install them.
This looks good, will need to create /etc/apt/apt.conf though, should do as root for correct ownership and security.
As a rule of thumb: if an 'apt-get -t unstable install' wants to remove any packages or upgrade/install lots of other packages, then abort the upgrade.
BTW. from the apt-get man page:
-t, --target-release, --default-release
This option controls the default input to the policy engine; it creates a default pin at priority 990 using the specified release string. This overrides the general settings in /etc/apt/preferences. Specifically pinned packages are not affected by the value of this option. In short, this option lets you have simple control over which distribution packages will be retrieved from. Some common examples might be -t '2.1*', -t unstable or -t sid. Configuration Item: APT::Default-Release; see also the apt_preferences(5) manual page.
NOTE: it is generally better to upgrade entirely to testing or sid (or backport a required package to stable) than it is to run a combination of stable + some packages from testing/unstable. You're far less likely to run into library quirks and version incompatibilities that way.
Have been reading this, repeatedly, and do understand. The best option will be for when it is released or official backport, but I need the scanner for tax documents due soon, and time cards. Hence wanting to do this weekend, if I can. I will try, but did hear helicopters, and near Bright. Bushfire is a concern, more than software, will be watching out on several matters.
Alternatively, download the debianised source for sane-utils and rebuild for debian 9. i.e. make your own backport.
That has potential, but would need the backport of the libsane as well. I am not yet sure of the development and build environment, nor whether I have the necessary installed yet.
Both the sane-utils and libsane packages are built from the same source package, "sane-backends".
BTW, if you use dpkg-buildpackage to build the packages, it will warn you if any build-dependencies are not met.
This is good to know, and what I shall start chasing for the moment.
If any of this is outside your comfort zone, then it would be better to just wait until either the new sane packages are in debian backports or until you upgrade to the next debian stable release. or ask someone you trust who runs debian stable to backport them for you.
If you want to extend your "comfort zone" then install debian stable into a VM and try either upgrading to testing or sid in there, or back-porting sane-backends inside the VM. That way you can get some practice without putting your system at risk. VMs are great for experimenting with stuff or learning new stuff that is potentially dangerous. Make one stable VM and then clone it for every new experiment - if it breaks, it's no big deal: just trash it and make another clone to try again.
I would, but not enough computer to run without thrashing. I would like a 16 or 32 Gb of memory machine, but finances are still tight. I would really like to get to the workshops, but even just the fuel is a stretch from NE Vic at the moment.
The easiest way to play with VMs is by installing the libvirt packages, allowing you to create and manipulate VMs and VM images with 'virsh' commands. The virt-manager package provides a GUI wrapper around virsh, which is good enough for most usage - there's a lot that virsh can do that virt-manager can't, but you're very unlikely to need any of those obscure/advanced features.
craig
I will make some more efforts and see where I get to, but shall turn off the radio, I do not like Tom Switzer and "Between the Lines" on Radio National, but almost everything else. Many thanks, Mark Trickett