All Sky Camera Revisited

[Gina]

gina@asc:~/AstroPi3$ ls /var/lib/dpkg
alternatives  diversions      lock           statoverride  triggers
available     diversions-old  lock-frontend  status        updates
cmethopt      info            parts          status-old
gina@asc:~/AstroPi3$ sudo rm /var/lib/dpkg/lock
gina@asc:~/AstroPi3$ ls /var/lib/dpkg
alternatives  diversions      lock-frontend  status      updates
available     diversions-old  parts          status-old
cmethopt      info            statoverride   triggers
gina@asc:~/AstroPi3$ sudo ./setupAstroPi3.sh

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~ Welcome to the AstroPi3 Raspberry Pi 3 Ubuntu-Mate KStars/INDI Configuration Script.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~ This will update, install and configure your Raspberry Pi 3 to work with INDI and KStars to be a hub for Astrophotography. Be sure to read the script first to see what it does and to customize it.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Are you ready to proceed (y/n)? y
dpkg is currently locked, meaning another program is either checking for updates or is currently updating the system.
Please wait for a few minutes or quit the other process and run this script again.  Exiting now.
gina@asc:~/AstroPi3$ ls /var/lib/dpkg
alternatives  diversions      lock           statoverride  triggers
available     diversions-old  lock-frontend  status        updates
cmethopt      info            parts          status-old
gina@asc:~/AstroPi3$ 

I get rid of it and confirm that but it comes back before or when the script is run!!

Edited April 1, 2019 by Gina

[Dr_Ju_ju]

go through the steps on here, (https://askubuntu.com/questions/219545/dpkg-error-dpkg-status-database-is-locked-by-another-process) to identify what else is running & kill it off...

 

[Gina]

sudo dpkg --configure -a  produced nothing.

[Dr_Ju_ju]

try a re-boot, then remove any remaining lock file, then re-try the update.

[Gina]

I can try that though I have rebooted a few times.  Trouble is... with Ubuntu Mate the Terminal history is not saved over reboots (unlike Mint) so I run Firefox to copy the commands from.  Could that be the problem - hasn't been before and I've used this process several times in the past though on v16.04.02 rather than 18.04.02.

[Gina]

Maybe I should return to the earlier Mate.

[Dr_Ju_ju]

On my 18's, history is saved.....  so something maybe wrong with your setup.... 

[Gina]

Oh!

[Gina]

Firefox is playing up on the RPi now - not getting "Submit Reply" in the editor.

Is your v18 beta?

[Gina]

Tried a reboot, ran Firefox to copy command lines to Terminal and tried removing the lock file without success as before.  Then closed Firefox so that couldn't interfere and tried again but no joy.  rm removed lock file and checked with ls followed by running the script and got the same lock error.

[Dr_Ju_ju]

is the script running as su ?  sounds like something is doing an update, which is stalling & locking dpkg. Is it possible to use apt instead ??

[Gina]

The command to run the script is :-

sudo ./setupAstroPi3.sh

[JamesF]

Recent releases of Ubuntu do a check to see if there are updates pretty much as soon as you log in.  It may be possible to disable that in the settings, but I don't know.  My recollection is that there's a process running called "unattended-upgrade" or something like that, and potentially a process called "http" owned by the "_apt" user.  It's all a bit of a faff, but I found it easiest just to let it finish.  Shouldn't take long these days, surely, now you have bandwidth coming out of your ears

If your terminal command history isn't being saved, it's possibly because the variables controlling it are not set up.  Probably the first place to start is to run

$ set -o | grep history

If that says "history off" then you possibly need to add "set -o history" to the end of your $HOME/.bashrc file.

James

[Gina]

I've checked what processes are running and there's nothing other than the System Monitor itself.

[JamesF]

Not sure what other processes there may be that are involved off the top of my head.  If the lock file is effectively being recreated when you remove it there must be something doing it, but what that process might be is hard to say.

If you can find the "software and updates" settings you can probably disable automatic updates there.  A reboot should then get you the system back without it running.

James

[Gina]

After a quick check to see if we're ready, the script starts off with a test of dpkg and the error message is coming from the script.  Script file is HERE

This is the relevant section :-

## check if DPKG database is locked
dpkg -i /dev/zero 2>/dev/null
if [ "$?" -eq 2 ]
then
    echo "dpkg is currently locked, meaning another program is either checking for updates or is currently updating the system."
    echo "Please wait for a few minutes or quit the other process and run this script again.  Exiting now."
    exit
fi

 

Edited April 1, 2019 by Gina

[Gina]

Seems to me the easiest option would be to go for the previous version of Ubuntu Mate and start over as there are several things wrong with the way the current system works.

[tekkydave]

12 hours ago, Gina said:

After a quick check to see if we're ready, the script starts off with a test of dpkg and the error message is coming from the script.  Script file is HERE

This is the relevant section :-

## check if DPKG database is locked
dpkg -i /dev/zero 2>/dev/null
if [ "$?" -eq 2 ]
then
    echo "dpkg is currently locked, meaning another program is either checking for updates or is currently updating the system."
    echo "Please wait for a few minutes or quit the other process and run this script again.  Exiting now."
    exit
fi

 

I suspect this dpkg command will always return a status of 2

On my Ubuntu 18.10 system:

$ sudo dpkg -i /dev/zero
dpkg: error: archive '/dev/zero' is not a regular file
$ echo $?
2

Try commenting this section out and try again.

In case anyone is unaware the command echo $? returns the exit status of the last executed command. A command that executes successfully should return a zero

 

Edited April 2, 2019 by tekkydave

[Gina]

That script has worked before with Ubuntu Mate 16.04, assuming the script hasn't changed.  I'll check that (if I can).

[tekkydave]

With dpkg running in another window (via the Synaptic Package Manager) I get:

$ sudo dpkg -i /dev/zero
dpkg: error: dpkg frontend is locked by another process
$ echo $?
2

This correctly returns a non-zero result. No idea why it doesn't when dpkg isn't running.

[Gina]

Hmm... the date on the script file is 2018 so it may be that I used an earlier version of the script.  Since the system is new and there should be nothing running when I try to run the script, I see no reason to check dpkg but Robert Lancaster (the author) knows much more about these things than me.

[tekkydave]

Is he contactable to find out?

[Gina]

Yes, I think so.

[Gina]

I can email him and also he used to be available on the INDI forum where I'm a member.  Meanwhile, I've written Ubuntu Mate 16.04 to the card and will try that.

[JamesF]

I would suggest that the script is incorrect.  dpkg can return an error code of 2 for any fatal error, not just if the system is locked by another process managing packages.  As the dpkg command in the script is an attempt to install from a file that isn't an actual package, that's a fatal error too.  Not really a smart way to go about checking

I've just checked and it behaves exactly the same way on Ubuntu 16.04, so I imagine the script will probably also fail there.

If you're happy that nothing is attempting to manage packages, I'd just comment that test out of the install script, Gina.

James