[Xquartz-dev] Class unable to view Qt5 Linux app using XQuartz

[f***@alumni.stanford.edu]

Dear XQuartz Developers,

I'm teach a class this quarter at Stanford where the main software package
we are using is running on Linux (RHEL 6). The application uses Qt5. The
students with Windows and Linux laptops are able to view the GUI just fine,
but the students with Macs using XQuartz (the majority) are having problems.

In particular, when the students try to do a copy, they get the error
message

QXcbClipboard::setMimeData: Cannot set X11 selection owner

and the copy doesn't work. When they quit the application, they get the
additional message

QApplication::qAppName: Please instantiate the QApplication object first

Do any of you have any ideas on how we could fix this? Not being able to
copy is a big disadvantage to code development.

Many thanks!

Bill

[Jeremy Huddleston Sequoia]

Those look like errors coming out of Qt, so I'd certainly start with a Qt mailing list.

Post by f***@alumni.stanford.edu
Dear XQuartz Developers,
I'm teach a class this quarter at Stanford where the main software package we are using is running on Linux (RHEL 6). The application uses Qt5. The students with Windows and Linux laptops are able to view the GUI just fine, but the students with Macs using XQuartz (the majority) are having problems.
In particular, when the students try to do a copy, they get the error message
QXcbClipboard::setMimeData: Cannot set X11 selection owner
and the copy doesn't work. When they quit the application, they get the additional message
QApplication::qAppName: Please instantiate the QApplication object first
Do any of you have any ideas on how we could fix this? Not being able to copy is a big disadvantage to code development.
Many thanks!
Bill
_______________________________________________
Xquartz-dev mailing list
https://lists.macosforge.org/mailman/listinfo/xquartz-dev

[f***@alumni.stanford.edu]

Dear XQuartz Developers,

I followed your advice and emailed the Qt mailing list. They looked at the
source code and are quite confident the the problem is with XQuartz.

My class is using XQuartz 2.7.8.
We are logging into RHEL 6 using ssh -Y forwarding (problem also with -X).
Our system has Qt5 version 5.4.0 and libX11 version 1.6.3.

I can provide you with any other information you need.

Our students with Linux and Windows laptops aren't having any problem, just
those with Macs using XQuartz.

I would greatly appreciate your help in fixing the problem. This is week 3
of our 10-week quarter.

Many thanks,

Bill


On Apr 12, 2016, at 10:22 AM, Thiago Macieira <***@intel.com>
wrote:

Interesting.

Well, looking at the source code, it seems that Qt is simply trying to set
the
selection owner for the given atom and failing. I see no reason *how* this
can
be Qt's fault.

Have you reported this as a bug? If not, please do and explain that it
happens
when ssh'ing from a Mac machine using XQuartz to a Linux one. Please
include
the SSH X11 forwarding configuration you're using (-X or -Y option or
whatever)
and whether other, non-Qt5 applications can set the clipboard. A good test
is
to run the xsel tool to get and set the clipboards.
--
Thiago Macieira - thiago.macieira (AT) intel.com
Software Architect - Intel Open Source Technology Center

On Apr 8, 2016, at 6:12 PM, Jeremy Huddleston Sequoia <***@apple.com>
wrote:

Those look like errors coming out of Qt, so I'd certainly start with a Qt
mailing list.

On Apr 8, 2016, at 14:57, ***@alumni.stanford.edu wrote:


Dear XQuartz Developers,

I'm teach a class this quarter at Stanford where the main software package
we are using is running on Linux (RHEL 6). The application uses Qt5. The
students with Windows and Linux laptops are able to view the GUI just fine,
but the students with Macs using XQuartz (the majority) are having problems.

In particular, when the students try to do a copy, they get the error
message

QXcbClipboard::setMimeData: Cannot set X11 selection owner

and the copy doesn't work. When they quit the application, they get the
additional message

QApplication::qAppName: Please instantiate the QApplication object first

Do any of you have any ideas on how we could fix this? Not being able to
copy is a big disadvantage to code development.

Many thanks!

Bill

[Ken Thomases]

What X error is Qt getting? Presumably, you'd need the Qt developers' help in learning that. Maybe Qt has a verbose logging setting. Which selection is it using?

They asked about the ssh X11 forwarding configuration. That would be useful for us, too.

Did you try installing xsel on the Linux system and running it with a Mac as the X server? What were the results?

Regards,
Ken

Post by f***@alumni.stanford.edu
Dear XQuartz Developers,
I followed your advice and emailed the Qt mailing list. They looked at the source code and are quite confident the the problem is with XQuartz.
My class is using XQuartz 2.7.8.
We are logging into RHEL 6 using ssh -Y forwarding (problem also with -X).
Our system has Qt5 version 5.4.0 and libX11 version 1.6.3.
I can provide you with any other information you need.
Our students with Linux and Windows laptops aren't having any problem, just those with Macs using XQuartz.
I would greatly appreciate your help in fixing the problem. This is week 3 of our 10-week quarter.
Many thanks,
Bill
Interesting.
Well, looking at the source code, it seems that Qt is simply trying to set the
selection owner for the given atom and failing. I see no reason *how* this can
be Qt's fault.
Have you reported this as a bug? If not, please do and explain that it happens
when ssh'ing from a Mac machine using XQuartz to a Linux one. Please include
the SSH X11 forwarding configuration you're using (-X or -Y option or whatever)
and whether other, non-Qt5 applications can set the clipboard. A good test is
to run the xsel tool to get and set the clipboards.
--
Thiago Macieira - thiago.macieira (AT) intel.com <http://intel.com/>
Software Architect - Intel Open Source Technology Center

Post by Jeremy Huddleston Sequoia
Those look like errors coming out of Qt, so I'd certainly start with a Qt mailing list.

Post by f***@alumni.stanford.edu
Dear XQuartz Developers,
I'm teach a class this quarter at Stanford where the main software package we are using is running on Linux (RHEL 6). The application uses Qt5. The students with Windows and Linux laptops are able to view the GUI just fine, but the students with Macs using XQuartz (the majority) are having problems.
In particular, when the students try to do a copy, they get the error message
QXcbClipboard::setMimeData: Cannot set X11 selection owner
and the copy doesn't work. When they quit the application, they get the additional message
QApplication::qAppName: Please instantiate the QApplication object first
Do any of you have any ideas on how we could fix this? Not being able to copy is a big disadvantage to code development.
Many thanks!
Bill
_______________________________________________
Xquartz-dev mailing list
https://lists.macosforge.org/mailman/listinfo/xquartz-dev <https://lists.macosforge.org/mailman/listinfo/xquartz-dev>

_______________________________________________
Xquartz-dev mailing list
https://lists.macosforge.org/mailman/listinfo/xquartz-dev <https://lists.macosforge.org/mailman/listinfo/xquartz-dev>

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