AppImage: sql delivers not loaded

[yschutz]

Hello,
From the AppImage built with travis:

At run time, the sqlite driver cannot be loaded:

QSqlDatabase: QSQLITE driver not loaded

and no available drivers is found.

In the AppImage these drivers are in usr/plugins/sqldrivers ...

What is going wrong ?

[yschutz]

@probonopd could you help me on this issue ?

[probonopd]

Were these drivers deployed automatically by linuxdeployqt or did you copy them in manually? Possibly they are missing (or not finding) dependencies. For debugging, please run with LD_DEBUG=libs ./Your.AppImage and watch out for errors.

[yschutz]

The drivers were automatically deployed by linuxdeployqt

[probonopd]

Thanks for the information. Do you see any errors when you run LD_DEBUG=libs ./Your.AppImage?

[yschutz]

apart of a few symbol lookup errors: undefined symbol related with gtk, I did not spot an error message before the "QSQLITE driver not loaded" message

[probonopd]

The GTK erros are probably caused by the GTK platform theme and unrelated. Please extract the AppImage (using --appimage-extract), then run strace -f ./squashfs-root/AppDir 2>&1 | grep -i sql, try to use some database functionality while watching for errors. Thanks.

[yschutz]

Thanks for your assistance... This is all what I get :

strace -f ./squashfs-root/AppRun 2&1 |strace -f ./squashfs-root/AppRun 2>&1 | grep -i sql
open("/home/schutz/Downloads/squashfs-root/usr/bin/../lib/libQt5Sql.so.5", O_RDONLY|O_CLOEXEC) = 3
write(2, "QSqlDatabase: QSQLITE driver not"..., 40QSqlDatabase: QSQLITE driver not loaded
write(2, "QSqlDatabase: available drivers:"..., 34QSqlDatabase: available drivers:
write(2, "QSqlDatabase: an instance of QCo"..., 85QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins

[probonopd]

Right when it is being launched, it says on the command line:

QSqlDatabase: QSQLITE driver not loaded
QSqlDatabase: available drivers:
QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins

The sqldrivers plugins seem to be there:

me@host:~$ find usr/plugins/sqldrivers/
usr/plugins/sqldrivers/
usr/plugins/sqldrivers/libqsqltds.so
usr/plugins/sqldrivers/libqsqlpsql.so
usr/plugins/sqldrivers/libqsqlodbc.so
usr/plugins/sqldrivers/libqsqlmysql.so
usr/plugins/sqldrivers/libqsqlite.so

libQt5Sql gets loaded:

me@host:~$ strace -f squashfs-root/AppRun 2>&1 | grep -i sql
openat(AT_FDCWD, "/home/me/squashfs-root/usr/bin/../lib/libQt5Sql.so.5", O_RDONLY|O_CLOEXEC) = 3

But for some reason libQt5Sql doesn't seem to load usr/plugins/sqldrivers/libqsqlite.so - at least using strace I can't see any attempt at opening it:

me@host:~$ strace -f squashfs-root/AppRun 2>&1 | grep -i sqldrivers

I don't know yet why that is. Other plugins are being opened, but not the sqldrivers.

[probonopd]

Actually, according to http://www.qtcentre.org/threads/48838-QSqlDatabase-an-instance-of-QCoreApplication-is-required-for-loading-driver-plugins! it gets fixed with

#include <QtCore/QCoreApplication>
QCoreApplication a(argc, argv);

[yschutz]

Thanks. I did see this one as well. However QCoreApplication does not allow to create a QWidget (The QCoreApplication class provides an event loop for Qt applications without UI)
So this cannot be the solution.

[probonopd]

Does it work for you before you run linuxdeployqt?

[yschutz]

Yes. I am developing on Mac. It works and the app created with macdeployqt works as well.

[probonopd]

Yes. I am developing on Mac. It works and the app created with macdeployqt works as well.

My question is, have you tested it on Linux without using linuxdeployqt? Then we would know for sure that linuxdeployqt is causing the issue.

[yschutz]

Yes, i have installed a Linux VM on my Mac. It works as it should from QtCreator.

[yschutz]

@probonopd just wondering if there is a solution to this problem .... thanks

[probonopd]

Sorry, Ihave not yet found the cause for why this is failing.

[yschutz]

Problem solved: it was in my code. Now I add the db as: db = addDataBase("QSQLITE") just before opening db. db is not anymore a data member of my dbhandler class. Not sure what exactly cause the pb

[probonopd]

Thanks for letting us know. This way others who might be running into the same issue will be able to find the solution here.

[yschutz]

@probonopd Thanks for helping on this and sorry for pointing in the wrong direction