I am trying to build QT libraries 4.8.2 on Ubuntu Linux by following the instruction mentioned in the documentation .
This is the second time I am trying building... I tried earlier also and when build process did not complete even after 12-13 hrs I thought something is wrong so I started from beginning.
It's been almost 24 hrs I issued make command (In the second attempt) the build process is still going on. Terminal is not showing any error either.
Does building QT libraries on Ubuntu Linux really takes this much time or I have missed something.
Building Qt takes a couple of hours even on a fast system if you only do the default non-parallel build. By default it also pulls in lots of libraries that you may not need.
So the first thing to try is make -j to do parallel builds. If that is still taking too long then try to slim down the libraries Qt generates. Do you need QtWebKit for instance? If you plan on using an embedded web browser in your application then you'll want it. If not then you can halve the time of your build. Type configure --help to see the options. Some useful ones that can reduce the build time are:
NOTE: some of the following options are no longer applicable in Qt5
-fast - Use this if you are just using Qt rather than developing Qt itself
-no-webkit - If you don't need the embedded web browser this makes a huge difference
-release - If you don't need the debug libraries then this can be quicker
-no-qt3-support - you won't need this for a new project
-nomake examples - don't build the examples
-nomake demos - don't build the demos
-no-declarative - If you're not using the QtQuick APIs then omit this
-nomake docs - don't build the documentation (this can save a lot of time)
If you're having to pay for the time in this Amazon instance then another option is to create a local Ubuntu machine (on a spare machine or in a virtual machine) and tweak the options there until you get something that works, then use that build configuration on your Amazon instance.
EDIT:
In Qt5, the project changed to use git submodules, so if you are building from a git checkout then the default behaviour is to clone all the submodules, which will add substantially to your build times if there are modules you don't need. There is a script init-repository that is part of the qt5 repository. You can use that to trim your local repository to only contain the submodules you need. So for instance:
git clone https://git.gitorious.org/qt/qt5.git
cd qt5
./init-repository --module-subset="qtbase qtdeclarative qtquick1"
configure --your-options-here
make -j
On my machine I can do a basic build of qtbase in about 10 minutes
memory requirements to compile Qt 4.7 are 1.2 Gb (mostly demanded by QWebKit link stage), if you don't have enough create an extra swap file (see https://www.centos.org/docs/5/html/5.2/Deployment_Guide/s2-swap-creating-file.html)
Related
I've recently installed Ubuntu 22.04 LTS on my development laptop. Previously I was running 18.04 so this is my first experience of Wayland. I did a clean installation on a new disc. I had relatively few problems reinstalling gitkraken and cloning the repository of my source code from github but when I came to install the Qt libraries this is where my problems started. The on-line installer from the Qt website simply wouldn't run. It just exited silently. I eventually found an old version of the on-line installer executable in a backup of my downloads folder from Ubuntu 18.04 and was able to use this to download and install the same version of the Qt libraries that I was using previously (5.15.0). This is also the same version that I use on my other development machine which runs Windows 10. Keeping the two in step is useful and upgrading too many things at the same time seemed like asking for trouble. I installed the latest versions of Qt Creator (7.0.1) and g++ (11.2.0).
I was then able to build my application and, after a brief search of stack overflow I added "-platform wayland" to the command line arguments setting in Qt Creator but the application crashed almost immediately on start-up with the error "The Wayland connection experienced a fatal error: Protocol error".
Several things made me think this might be a bug in the Qt libraries rather than my application (none of them definitive!):
At the point of application exit, apart from main() there is none of my application code in the call-stack (see below)
My application has been stable for a long time and has survived several operating system, compiler and Qt version changes across two OS families
The fact that the latest Qt on-line installer (itself almost certainly a Qt application) wouldn't run
I downloaded Qt 5.15.12 (the latest Qt 5 version available) and rebuilt my application against that but the result was the same.
The next step is obviously to strip my application right down to something minimal that still shows the problem but before I do I was wondering whether this is something other people have come across when migrating a Qt5 application to Wayland and whether I need to take the bigger step of upgrading to Qt6? The Qt Wiki describes Qt 5.11 as being "stable" with Wayland.
The call stack at the time of the error looks like this:
qt_message_fatal
QMessageLogger::fatal
QtWaylandClient::QWaylandDisplay::checkError
QtWaylandClient::QWaylandDisplay::flushRequests
doActive
QMetaObject::activate
QSocketNotifier::activated
QSocketNotifier::event
QApplicationPrivate::notify_helper
QApplication::notify
QCoreApplication::notifyInternal2
QCoreApplication::sendEvent
socketNotifierSourceDispatch
g_main_context_dispatch
??
g_main_context_iteration
QEventDispatcherGlib::processEvents
QEventLoop::exec
QCoreApplication::exec
main
Many thanks.
It's something to do with QDialog::setMaximumSize. The call to setMaximumSize itself does not crash but if I remove all calls to it the application works fine. Some controls do subjectively seem bigger on Wayland so I wonder if Qt 5 on Wayland crashes if the size of the QDialog contents exceeds the maximum size specified. This certainly doesn't cause a crash in Qt 5 on Windows and didn't in Qt 5 on Ubuntu prior to the switch to Wayland. I think this is a Qt bug but of course it may well be fixed in a later version of Qt and there's an easy enough work-around now I know the cause.
I was using setMaximumSize to allow the dialog to expand dynamically as widgets were added but to prevent the user from making the window any bigger than it needed to be. layout()->setSizeConstraint(QLayout::SetFixedSize); achieves the same thing.
I currently have a Java application packaged in an RPM that gets built for 32-bit RedHat platforms, and I want to create a 64-bit RPM, which is largely just the same as the 32-bit one, but with a couple different .so files included. All the Java stuff is the same on both platforms, so it's just JNI .so's.
My question is: Is it possible to have rpmbuild on a 32-bit system generate both the 32-bit and 64-bit RPMs (from different .spec files) since it's just repackaging already-built components, or do I need to build the 64-bit RPM on a 64-bit system?
N.B. I'm not actually building anything native on the system. I'm just repackaging stuff that's already built.
... or vice versa, can I build a 32-bit one on a 64-bit system? I really would prefer just to build and package this on one system than have two separate builds run for the separate RPMs.
As Aaron stated you can build an RPM for multiple distros on the same machine (64-bit), but you have to be very careful or you can run into issues. The biggest problem I've run into is you build on RHEL 5, then you try to deploy to RHEL 6, since RHEL 6 has a different version of RPM installed, it can cause conflicts and fail to install. So in this scenario you have a few options:
Build the RPM on two machines, you've stated you don't really want to do this.
If you have the disk space, configure Mock, I've used it a ton before and it's really easy to get going as long as you have the disk space and the package spec was designed to pull in requires properly.
Personally I'd give Mock a shot, it's quite simple to set up, and will allow you to do what you want with minimal effort as long as the proper repos are available. In the event the build fails the log is pretty comprehensive regarding what the RPM build error was.
I am involved in development of a large cross platform project that build for Windows, Linux, and Mac OS X. The build for the software is configured with CMake.
The CMake scripts have been designed to configure successfully for Visual Studio on Windows, and Makefiles are currently used for building on Linux and Mac OS X.
Pretty much all of the development for the project so far has been done with people working on Windows, and a little bit of work on Linux. I am interested in developing for the project using Xcode 4.6 on a Macintosh running Mac OS X 10.7, and I have encountering problems as the CMake files do not seem to configure properly for that development environment.
For non-windows platforms many custom commands have been written to try to configure things such as copying needed files or setting environments that are needed for certain operations such as running unit tests during the build process.
It seems that because Xcode is an integrated development environment simliar to Visual Studio is has this concept of a build configuration, and when software gets build output files in up in a directory path that includes that configuration concept (i.e. many build files end up in a path that ends with folder named something like Debug, Release, etc.)
CMake is supposed to have support for dealing with this build configuration concept and the mechanism utilized work well for Visual Studio. That do no seem to work for Xcode. For example our build engineers have design CMake scripts so that for Windows, many path and whatnot are configured using the CMAKE_CFG_INTDIR value which helps to qualify the build configuration.
The use of CMAKE_CFG_INTDIR is not working for Xcode as the script for Macintosh were written with Makefiles in mind which don't really have the build configuration concept. The use of CMAKE_CFG_INTDIR within custom commands used to configure things fails on the Macintosh as the value resolves to $(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME). This values are not define when the custom commands are run, so values are not set properly and build operations fail.
It is unclear what is needed so that the system can successfully configure for Xcode. Searching on the Internet so far has not yielded insight into what should be used to make sure that build configuration can be successful. What resources are available that would help in figuring out how to configure this project to build with Xcode?
If you're talking about custom commands set using add_custom_command, then you should prefer "generator expressions" to avoid issues regarding per-configuration build directories. From the docs for add_custom_command:
Arguments to COMMAND may use "generator expressions" with the syntax "$<...>". Generator expressions are evaluated during build system generation to produce information specific to each build configuration.
For example, the build directory for a target called "MyExe" could be referred to as $<TARGET_FILE_DIR:MyExe>
Generator expressions are available in a few CMake commands, not just add_custom_command.
If you have more specific problems, it's maybe worth asking further question(s) with the relevant details.
In a nutshell, the question is: I just finished my first application using Qt Creator on a computer running under Linux Ubuntu, now how do I make this available for everyone. Now follows the more detailed version ;)
I must apologize for asking this, I am aware that this question has probably been asked many times and that there is official documentation that I can read. I am just completely new to programming and I am very confused by everything I've read so far. If you are kind enough to help, please assume I know absolutely nothing :)
Here we go: I've just finished designing my first application (a scientific program) with Qt creator on my laptop which runs under Linux Ubuntu. It works fine and I'm very proud of it ;)
Here's what my project consists of: 40 header files, 42 source files, 1 pro file, 1 qrc file, 1 html file and 7 png files. In the code, I use #include for a bunch of fairly standard Qt classes (QWidget, QTextBrowser and so forth, maybe like 40 of those).
Now I'd like to make it available to other people. For Linux and Mac users, I've figured a way to do that: I can compress the folder containing my project, tell them to install Qt on their computer, then download and extract the files on their hard disk, open a terminal in the folder and run
qmake myProject.pro
qmake
make
That seems to work fine (by the way, does it matter that this is not precisely what Qt creator does? The qmake step there is qmake-qt4 myProject.pro -r -spec linux-g++ and the make step is make -w). Now, I assume there is a solution where I don't ask them to download and install something like 200Mo of Qt material. As for Microsoft Windows users, I don't have a clue.
I would be very grateful if you could explain to me in a very concrete way what I need to do. Needless to say, I'll go for the best and easiest solution, I don't need to understand everything about deployment. Many thanks in advance!
Edit: In case that's useful : I've been using Qt Creator 2.5.0 based on Qt 4.8.1 (64 bit), I'm working on a laptop with Ubuntu 12.04 64bits
For Linux and Mac users, I would compile the software for them in 32 and 64bit formats - no-one likes compiling unknown software from source. Obviously keep the source code option for those on more unusual architectures/OSs (and provide a shell script for them that mimics the commands Qt Creator calls!). As Qt runtimes are available from package managers on just about every distro (and come pre-installed on most anyway, KDE requires them for example), by not asking them to compile from source your users will have a much smaller download (if any) and won't require them to download software from a website potentially unknown to them. Of course the best way would be to try to get your software added as a package into the major distros' repositories, but that may take some time to organise.
Compile your software for Windows users for both 32 and 64bit formats. It's generally frowned upon to ask users to download runtime libraries they potentially don't know, and put them into their system32 folder... So most applications bundle all the libraries they need with their application. Qt-based applications are no different, and so put the runtimes into the folder where the executable is. Also it is much more professional to create a proper installer, there are a few free installer applications for Windows, a web search will give you the most popular (I think I saw a thread on SO about it as well).
As you can see the platforms aren't too dissimilar, the main point I would make is: Do not force people to compile from source! The vast majority of people on Earth do not even know what compiling is, so provide for the major arrchitectures/OSs yourself.
I've been coding with Python and C++ and now need to work on building a gui for data visualization purposes. I work on Mac Snow Leopard (intel), python 3.1 using gcc 4.2.1 (from Xcode 3.1)
I wanted to first install Qt and then PyQt. And my goals are to be able to:
- quickly prototype GUI and the accompanied logic that drives the GUI using PyQt and python
- if I decided I need the speed, or if it's fairly easy to translate my GUI into C++ using the Qt tools, I have the options to translate my app into C++
- Be able to deploy my application onto Windows (both the python and c++ version of my app)
Give the goals above, what are the correct steps I should take and what issues i should be aware of when setting up Qt and PyQt. Which other deployment tools do I need?
From my readings so far, here's what I have:
download the Qt source for mac and configure it with
-platform macx-g++42 -arch x86_64 -no-framework
(i've read somewhere that
building as framework causes some
trouble in deployment and/or
debugging, can't find the article
anymore)
download latest SIP source and build
download latest PyQt and build from source (any special options I should pay attention to?)
For deployment, I've read that I would need to use py2exe/cx_freeze for windows, p2app for mac:
http://arstechnica.com/open-source/guides/2009/03/how-to-deploying-pyqt-applications-on-windows-and-mac-os-x.ars
but seems like what the article describe is deploying an app you build on windows on the windows platform and vice versa. How do you deploy to windows (is it even possible?) if you are writing your Qt app on a mac ?
Really appreciate the help
I'm guessing by deploying, you mean a compiled version to users that have no Python or Qt or anything.
I'm been trying py2app for a while now and never really worked out for me. You can try PyInstaller. It worked out pretty well for me since it's made to work with plugins like PyQt and PIL etc. I put up some instructions here
http://tech.xster.net/tips/deploy-pyqt-applications-on-mac-os-x-with-pyinstaller/
They don't really support cross-compilation though. Just recently, they made cross-compilation for windows binaries on linux possible. If you want to spend some time hacking it, it's probably possible. But probably easier just to get a windows machine and building a binary with it.