Re: LilyPond v2.20.0 on Raspberry Pi OS (Debian buster)

[David Wright]

On Sat 21 Nov 2020 at 16:20:55 (+0100), Jean Bréfort wrote:
> Le samedi 21 novembre 2020 à 15:57 +0100, renyhp a écrit :
> > On 21/11/20, 15:08 > > Jean Bréfort <jean.brefort@free.fr> wrote:
> > > Le samedi 21 novembre 2020 à 10:52 +0100, renyhp a écrit :
> > > > I have installed LilyPond v2.18.2 on my Raspberry Pi 4 from the
> > > > repositories, and I now would like to upgrade the current stable
> > > > version.
> > > > 
> > > > The arm architecture of the Raspberry Pi does not make it possible
> > > > to use the installer on the website.
> > > > 
> > > > The repositories for Raspbian and Debian do include arm builds, but
> > > > the buster repositories are still on v2.18.2.  
> > > 
> > > but the ones for testing do include 2.20.0
> > > (https://packages.debian.org/bullseye/lilypond)
> > 
> > Yes, they do, but I can't just download the deb file from there and
> > install it, can I? In my understanding, there will be some dependencies
> > and my software will try to resolve them by looking at the buster
> > repository, and will most likely fail (as, for example, the
> > lilypond-data package is required to be 2.20.0-2 which is still not in
> > the buster repositories). Besides, I don't think it would be wise to
> > change my system-wide apt source just for LilyPond.
> > 
> > But I hope someone can prove me wrong on anything I've just said.
> 
> Download the .deb and install it with dpkg. That will give you the list
> of missing dependencies that you'll need to download manually and
> install. This is somewhat time consuming and even might fail but it's
> the only way I know.

Whoa, don't do that: it puts you on the path to a Frankendebian.
https://wiki.debian.org/DontBreakDebian
Do this instead:

axis!david ~ $ apt -s install /home/debian/bullseye/lilypond_2.20.0-2_amd64.deb¹
NOTE: This is only a simulation!
      apt needs root privileges for real execution.
      Keep also in mind that locking is deactivated,
      so don't depend on the relevance to the real current situation!
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Note, selecting 'lilypond' instead of 
'/home/debian/bullseye/lilypond_2.20.0-2_amd64.deb'
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 lilypond : Depends: lilypond-data (= 2.20.0-2) but 
2.19.81+really-2.18.2-13+deb10u1 is to be installed
            Depends: libc6 (>= 2.29) but 2.28-10 is to be installed²
            Depends: libcrypt1 (>= 1:4.1.0) but it is not installable
            Depends: libgcc-s1 (>= 3.0) but it is not installable
E: Unable to correct problems, you have held broken packages.
100 axis!david ~ $ 

Note that this can be done as a user ($) rather than root (#).
The kicker is libc6 of course. Looking at its reverse dependencies:

axis!david ~ $ apt rdepends --installed libc6 2>/dev/null | grep 'Depends: ' | 
wc -l
1350
axis!david ~ $ 

That's 1350 packages, out of 2064 in total, that depend on libc6.

My own solution would be to consider either dual-booting the Pi4
with buster and bullseye (I always set my disks up with two root
filesystems), or acquiring a second Pi.

----

Notes:

¹ The install command must have an argument starting with
  / or ./ or ../ to make apt recognise it as a *file* name
  rather than a package name. This form is not well
  documented.

² "is to be installed" might be confusing in this context:
  it includes packages already installed.

Cheers,
David.