Kubuntu backports ppa breaks musecore

• Feb 6, 2016 - 22:41

I'm not sure if this is even the place to post this, so I apologize in advance.

I'm on Kubuntu 15.10 with backports enabled. This, of course, keeps my version of Plasma updated.
Also, as an obvious side-effect, my version of QT has been updated to version 5.5. This apparently breaks installation of musescore as I get the following output:

ron@sisko:~$ sudo apt-get install musescore
Reading package lists... Done
Building dependency tree
Reading state information... Done
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:
musescore : Depends: qtbase-abi-5-4-2
E: Unable to correct problems, you have held broken packages.

I've tried checking for held broken packages. There are none according to apt.
I've tried switching from stable to nightly builds of musescore. Dependency is still on QT 5.4
Tried installing libqtcore5a (provides the dependency). Shockingly it installed using dpkg, but it
caused too many other dependency issues with Plasma.

Two questions:
1. Will there be a dependency upgrade soon, or is that a ways down the road?
2. Is there some other way to install this as even the official Ubuntu repos are outdated?


Comments

I can't rebuild the wily package against Qt 5.5.1 or it would break for Wily users who haven't enable backports. Enabling backports is an unsupported configuration for precisely this reason, but there are some (unsupported!) tricks you can do to get hold of an updated copy:

  1. Temporarily enable the Xenial repos, upgrade MuseScore, then disable the Xenial repos again. VERY IMPORTANT - DO NOT KEEP THE XENIAL REPOS ENABLED!
  2. Manually install the .deb package for MuseScore on Xenial (i.e. this file).

It seems that MuseScore isn't available in the Xenial repos just yet so you'd have to go for the second option. (Once it becomes available in the Xenial repos it's possible that it would become available in backports too, but I'm not sure.)

In reply to by barbosabyte

@dorien, did you revert back to your original setup first (i.e. remove MuseScore and Qt 5.4?)
If not, do:

sudo apt-get remove --purge musescore
sudo apt-get autoremove --purge

Then manually install the deb file, and if necessary do this afterwards:

sudo apt-get install musescore-common

I don't think option 1 will work just yet - it doesn't look like the package has found its way into the official Xenial repo just yet.

If none of those work, you could try out one of our new portable AppImages which include the right Qt in the package and are more-or-less guaranteed to work. MuseScore 2.0.3 will be released as an AppImage when it arrives, and you can get a preview build here for 32 bit or 64 bit. Simply download and give execute permission:

chmod u+x MuseScore*.AppImage

In reply to by shoogle

Hmmm....

I must be living under a rock. Never heard of AppImages. :P
Loving what I'm seeing though. I tried option 2 on your original post and that worked for me.
Didn't have time to reply before you made this post, and now I'm wondering which one I should stick with. Decisions, decisions, decisions.... ;)

Anyway, I just wanted to thank you guys for such a great piece of software and for the help you've given. Wishing you and yours the best!

Not sure how to mark this thread as solved ...

In reply to by shoogle

AppImages are a relatively new packaging format that's only just starting to get noticed. The idea is that they get built on one Linux distro but then run on every other distro too (usually Linux programs only run on the distro they were compiled on). See http://appimage.org/

Stick with the normal package for your regular score editing if it's working for you, but feel free to give the AppImages a try just to test. You can have them on the same machine as the Ubuntu package without causing problems.

In reply to by shoogle

Thanks for the suggestion!

I did the purge-thing you suggested.

After installing the deb I did get:

dpkg: error processing package musescore (--install):
dependency problems - leaving unconfigured
Processing triggers for hicolor-icon-theme (0.15-0ubuntu1) ...
Processing triggers for man-db (2.7.4-1) ...
Processing triggers for desktop-file-utils (0.22-1ubuntu3) ...
Processing triggers for mime-support (3.58ubuntu1) ...
Processing triggers for shared-mime-info (1.3-1) ...
Unknown media type in type 'all/all'
Unknown media type in type 'all/allfiles'
Errors were encountered while processing:
musescore

It does work, but very slow and crashes a lot. I think I might look into the appimage. Very cool info on that btw!

In reply to by dorien

Possibly. Could you run this command to see if there's something missing on your system:

./MuseScore*.AppImage check-depends > dependencies.txt

This will create a file "dependencies.txt" that you can upload to this forum for us to diagnose (click on "File attachments" when you write your reply).

However, I am surprised that it runs slowly rather than simply not working. Is it just slow to start up or is it also slow once it is running? Do you have a solid state drive or a normal hard drive?

You could try disabling the Start Centre and Splash Image in MuseScore's Preferences and also click "Start empty" instead of loading a score on startup.

In reply to by shoogle

Thanks for your suggestion. I've attached the output of the depends command.

I've disabled the start centre but it makes no difference. I timed it and it takes about 30 seconds for anything to happen (e.g. showing musescore in the task manager).

I have a solid state drive. Fairly new laptop that otherwise works pretty fast.

I am using Kubuntu, but I think I used the correct package:

>> lsb_release -a
LSB Version: core-2.0-amd64:core-2.0-noarch:core-3.0-amd64:core-3.0-noarch:core-3.1-amd64:core-3.1-noarch:core-3.2-amd64:core-3.2-noarch:core-4.0-amd64:core-4.0-noarch:core-4.1-amd64:core-4.1-noarch:security-4.0-amd64:security-4.0-noarch:security-4.1-amd64:security-4.1-noarch
Distributor ID: Ubuntu
Description: Ubuntu 15.10
Release: 15.10
Codename: wily

Attachment Size
dep.txt 7.1 KB

In reply to by dorien

Dependencies all seem to be present and correct, but your kernel is slightly older than mine so you might want to try doing a sudo apt-get update && sudo apt-get upgrade. However, I noticed that MuseScore (both AppImage and the Ubuntu package) can sometimes take a while (10s-30s) to start on my machine (64 bit, Core i5, Ubuntu 15.10, SSD, 4GB RAM), but it runs just fine once it has started up.

The AppImages are compressed (from ~140MB down to ~70MB) so when you run them the first thing that happens is they have to be decompressed, but this doesn't take long and it can actually be faster sometimes to decompress than read a whole file into memory from disk (which happens when you run the Ubuntu package). The AppImage also has a few helper scripts that have to run before the main program can start, but these should be almost instantaneous. You can see how long the decompression and helper scripts take if you launch with an option that will suppress the GUI, such as ./MuseScore*.AppImage man (which shows the man page).

The long startup time is probably mainly due to the linker having to load lots of libraries, some of which (like Qt) are very large and link against yet more libraries. Unfortunately, there's not much that can be done about this really, at least in the short term, and that is a problem with both the AppImage and the Ubuntu package.

So if MuseScore is slow to start up but runs smoothly afterwards then I don't think there's much we can do. But if you find it is still slow even after it has launched then try running it from the terminal and report any error or warning style messages that show up in the terminal window when you try to use different features within the program.

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