Using qmake without Qt Overhead? - qt

We have some smaller libraries we use in our bigger project quite often.
Still we compile and run the unit tests of these smaller libraries as independent CI Jobs.
Most of these libs use QMake as buildtool, not using Qt in any way. And we started to move our CI-Jobs into docker containers. Now I realized that I always have to get qt5-default (on Ubuntu 16) for qmake to work. Is this intended? This gives quite a signifacant overhead. Does anybody know a way, to use qmake on Ubuntu 16 wihtout getting the whole Qt instalation on board?

You don't actually need Qt installed for qmake to work. The reason why you need qt5-default is that most linux distributions provide both Qt5 and Qt4, which have the same binaries, for example they both have a version of qmake, which would both get installed to /usr/bin. In order to fix that problem Qt5 installs to /usr/lib/.../qt5 and Qt4 to /usr/lib/.../qt4, and the qt5-default package creates symlinks from there to /usr/bin
For Ubuntu , ... is x86_64-linux-gnu!
You can choose between:
Install only the qt5-qmake package in your docker container and create a symlink /usr/bin/qmake -> /usr/lib/.../qt5.*
Specify the full path to the qmake binary when building your software, inside your {travis, gitlab, jenkins} CI config
Add /usr/lib/.../qt5/bin to your $PATH
* The proper place for a manually created symlink would actually be /usr/local/bin because if you have the symlink in /usr/bin, installing qt5-default package would fail because the symlink qt5-default wants to create would already exist. However, you are in a docker container and can actually control whether qt5-default gets installed, and if you create the symlink in /usr/local/bin you have to make sure to add /usr/local/bin to your $PATH, which is overkill for that scenario.

Related

Statically installing Qt4 such that OpenCV can detect the installed Qt4 libraries

I am currently using Ubuntu 14.04 LTS.
How can I statically build Qt 4.8.5 -
https://download.qt.io/archive/qt/4.8/4.8.5/qt-everywhere-opensource-src-4.8.5.tar.gz
such that when I cmake OpenCV 2.4.13 -
https://github.com/opencv/opencv/archive/2.4.13.zip
it correctly identifies the location of Qt4 ?
When I cmake OpenCV after I have installed Qt4 in /usr/local/qt4-static/, the find_package(Qt4 REQUIRED QtCore QtGui QtTest) function call within opencv-2.4.13/cmake/OpenCVFindLibsGUI.cmake fails because it cannot find qmake. Also, upon running the qmake -query in the terminal, Ubuntu says that qmake is not installed, when it clearly in /usr/local/qt4-static/.
How should I go about this so OpenCV cmake correctly recognizes Qt4 ?
Build Qt
Extract the source-code and run ./configure && make and then sudo make install. It should create all necessary configuration to run qmake in any folder (system-wide).
Additional: create a symlink/export (use only if make install did not work for you)
You need to promote qmake to $PATH or create a symlink, but this is usually done when you run sudo make install after make in the Qt source-folder.
root:/home# echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:
Symlink (permanently)
ln -s /path/to/qmake /usr/sbin/qmake
or
export (temporary)
export PATH=$PATH:/folder/of/qmake
Afterwards qmake -v is working whereever you are
root:/tmp qmake -v
QMake version 3.1
Using Qt version 5.10.1 in /usr/local/Qt-5.10.1/lib
If your project still cannot determine the location of Qt, read the pro/pri/cmake file to understand how it looks for the path.

Where to install "guile-git" on Ubuntu 14?

I got stuck installing "git clone https://gitlab.com/guile-git/guile-git.git". In which directory is this supposed to be cloned and installed?
Dunno if you're still looking for an answer but it doesn't seem you need this installed to install guix; the read-me of the repository says that you can install it via guix. guix is an agnostic package manager that you can install on any Linux distribution alongside the default package manager and guix is the default package manager of the GuixSD operating system (https://www.gnu.org/software/guix/).
If you're on a distro which doesn't use guix, you may not want to install guix (I've yet to find reason enough to, yet); if you use a lot of GNU tools or Guile (some Guile packages are available through guix), you may want to.
Most repositories that don't have a binary for you to run follow the build process of configure, make, and [sudo ]make install.
I cloned the repository, myself, and find that this one does, as well.
Get a terminal (if you haven't been using one, yet) and cd into the directory you cloned the repository to and then cd into the guile-git directory (cd guile-git).
If we do ls -l, we'll see that the only executable file there is the bootstrap one; I've never seen one before but doing ./bootstrap generates the configure file and sets up the make process for us. So now back in familiar territory.
Given these are Guile files, we'll probably want to install this under the same prefix as where Guile is installed so run which guile. I believe, if you install it under Ubuntu (I'm running Linux Mint), it'll install to /usr/bin/ but, if you install it manually, it'll install to /usr/local/bin/.
The latter is where mine is and that's the default prefix that configure uses so I can just do ./configure; if you wanted to install it under /usr/, run /.configure --prefix=/usr/.
This'll verify that all of the necessary libraries and programs that guile-git needs are installed and properly setup. Heads up that configure balked at me over not having the Guile module bytestructures installed (https://github.com/TaylanUB/scheme-bytestructures) so you may need to do that.
I'm not going to run through everything to get it installed but, once you can run it without any errors, run make to build it within the directory.
If you want to install it permanently on your computer with the rest of your operating system able to detect it, run make install. Since you'll likely've specified a directory under /usr, you'll have to do sudo make install so that the make process can have permissions to install under /usr/local or /usr.
Sorry if I reiterated anything you already knew; 'just didn't want to assume you knew something and result in confusion.

Get Qt5 up and running on a new Mac

Coming from Ubuntu I bought a new iMac and tried to setup my Qt development. Everything else is already up and running. Xcode command line tools are also installed.
Because it surprised me how good brewand brew caskworked I wanted to install Qt5with them. On the one side it is very fast and I do not have to got to any homepage in order to download it. On the other side I do not have to care about the installation directory. Having multiple version installed should also be a lot simpler though.
I used the following commands:
brew install qt5
brew cask install qt-creator
Qt5 is now installed under /usr/local/Cellar/qt5/5.4.1. I also added the bin folder to my path (done in .bash_profile). QtCreator, Linguist and all the other applications are shown in my launchpad. But unfortunately, it is still not done.
QtCreator says that no version of Qt is known. I tried to add qmake but I was not able to navigate to the folder mentioned above.
Could anybody give me a hint on how to fix this issue? Installing qt via installer should be the last option.
I had similar issue with Qt Creator, now on Mac GUI applications do not have access to environmental variables (in previous versions it was different).
You need to setup path to qmake in Qt Creator manually using Command-Shift-G in Finder to navigate to Folder you need.
Another option is to use brew link qt5 --force, which will symlink the various Qt5 binaries and libraries into your /usr/local/bin and /usr/local/lib directories. This will give you qmake at the command line, without requiring you to add anything special to your path in .bash_profile. The main reason this isn't done by default is that Qt4 is also somewhat popular.
It could get a little messy, but if you need to install Qt4 as well, you can unlink Qt5 at any time, by doing brew unlink qt5, and it will keep the installation intact. Then do brew install qt to get Qt4, which unlike the brew installation for Qt5 will indeed create the links directly into /usr/local without you having to manually do brew link qt. You can unlink Qt4 and relink Qt5 (or vice-versa) whenever you need to switch.
In my cases I needed to set it in Preferences => QT Versions => Add. Environment variables also did not help. Small popup when starting app also did not work.
I use command like this:
brew install qt#5
and. success install qt5 by brew.

Running JavaFX applications on Redhat 5

From my previous question, I know that JavaFX is not supported in RedHat 5.8 meaning, even when I have Java 8 (jdk1.8.0_05) installed on my Linux, a JAR file created in win7 can't be executed via java -jar helloworld.jar. Does that mean there is NO way to run JavaFX jars on this machine?
The problem with running JavaFX applications on RHEL5 is the version of glib that comes with that OS is not new enough. The trick, then, is to provide a newer version of that library and all of the other libraries that depend on it to the JRE. The next hurdle is that RHEL5 shared library loader won't load those libraries. You have to use a compatible loader. But the JVM has the path to the loader hard-coded in the executable! So you need a separate JVM with a custom loader path patched in. Roughly, the steps to get this working are...
Unpack the following packages from RHEL6:
glib2
libffi
glibc
glibc-common
zlib
gtk2
pango
cairo
pixman
Put all of the shared libraries from those packages in a directory on your RHEL5 system. Let's call it /YOUR-ALIEN-RHEL6-LIBS-PATH.
Unpack another copy of a JRE to, say, /YOUR-ALIEN-JVM-PATH.
Use patchelf to point the JVM executable to the new loader.
./usr/bin/patchelf --set-interpreter /YOUR-ALIEN-RHEL6-LIBS-PATH/lib/amd64/ld-linux-x86-64.so.2 /YOUR-ALIEN-JVM-PATH/jre1.8.0_25/bin/java
Run the application after setting LD_LIBRARY_PATH=/YOUR-ALIEN-RHEL6-LIBS-PATH/lib/amd64:/YOUR-ALIEN-RHEL6-LIBS-PATH/lib/amd64/jli
Although it is not pretty, I have successfully run JavaFX applications on RHEL5 using this method. Having said that, I highly recommend just upgrading your OS if it is even remotely feasible.
Note this builds upon the existing answer from James with more concrete detail
Obtain RPMs from a RedHat 6.x, e.g. http://vault.centos.org/6.2/os/i386/Packages. Copy into directory rpms/
cairo-1.8.8-3.1.el6.i686.rpm
glib2-2.22.5-6.el6.i686.rpm
glibc-2.12-1.47.el6.i686.rpm
glibc-common-2.12-1.47.el6.i686.rpm
gtk2-2.18.9-6.el6.centos.i686.rpm
libffi-3.0.5-3.2.el6.i686.rpm
libXcomposite-0.4.1-2.el6.i686.rpm <== not mentioned in other answer
pango-1.28.1-3.el6_0.centos.5.i686.rpm
pixman-0.18.4-1.el6_0.1.i686.rpm
zlib-1.2.3-27.el6.i686.rpm
libXdamage-1.1.2-1.el6.i686.rpm <== not mentioned in other answer
Extract all the contents from the RPMs into separate directory. Use rpm2cpio and xzcat. xzcat can be installed from these RPMs if necessary [xz, xz-libs, xz-lzma-compat]
mkdir redhat-6u2-libs
cd redhat-6u2-libs/
ls -1 rpms/* | xargs -i{} bash -c "rpm2cpio {} | xzcat | cpio -idmv"
Obtain copy of patchelf. I built from source as couldn't find a Redhat 5 RPM. Only requires dependent RPMs [gcc, gcc-c++, glibc-devel, kernel-headers, libstdc++-devel]
wget https://nixos.org/releases/patchelf/patchelf-0.9/patchelf-0.9.tar.bz2
tar xjf patchelf-0.9.tar.bz2
cd patchelf-0.9
./configure --prefix /tmp/patchelf
make install
Use patchelf to set location of redhat 6u2 loader (aka interpreter)
/tmp/patchelf/bin/patchelf --set-interpreter ~/redhat-6u2-libs/lib/ld-linux.so.2 jdk1.8.0_40/bin/java
Set LD_LIBRARY_PATH, this needs to have both /usr/lib and /lib, otherwise you get a segfault.
export LD_LIBRARY_PATH=/home/user/redhat-6u2-libs/usr/lib:/home/user/redhat-6u2-libs/lib
(Note that any other applications run after LD_LIBRARY_PATH is set other than java which has had its interpreter location corrected will segfault.)
Now run java app...
./jdk1.8.0_40/bin/java -cp etc...
Happy days

In Qt Creator, examples are missed

Installed Qt Creator 2.8 in ArchLinux
Installed qt5-* (* as every related package) using pacman
examples were not available in the repositories so I used the one in the AUR, qt5-examples
examples are installed under /usr/share/doc/qt/examples
qmake-qt5 -query says:
QT_SYSROOT:
QT_INSTALL_PREFIX:/usr
QT_INSTALL_ARCHDATA:/usr/lib/qt
QT_INSTALL_DATA:/usr/share/qt
QT_INSTALL_DOCS:/usr/share/doc/qt
QT_INSTALL_HEADERS:/usr/include/qt
QT_INSTALL_LIBS:/usr/lib
QT_INSTALL_LIBEXECS:/usr/lib/qt/libexec
QT_INSTALL_BINS:/usr/lib/qt/bin
QT_INSTALL_TESTS:/usr/tests
QT_INSTALL_PLUGINS:/usr/lib/qt/plugins
QT_INSTALL_IMPORTS:/usr/lib/qt/imports
QT_INSTALL_QML:/usr/lib/qt/qml
QT_INSTALL_TRANSLATIONS:/usr/share/qt/translations
QT_INSTALL_CONFIGURATION:/etc/xdg
QT_INSTALL_EXAMPLES:/usr/share/doc/qt/examples
QT_INSTALL_DEMOS:/usr/share/doc/qt/examples
QT_HOST_PREFIX:/usr
QT_HOST_DATA:/usr/lib/qt
QT_HOST_BINS:/usr/lib/qt/bin
QT_HOST_LIBS:/usr/lib
QMAKE_SPEC:linux-g++
QMAKE_XSPEC:linux-g++
QMAKE_VERSION:3.0
QT_VERSION:5.1.0
which means examples are in the right place
But they are not shown in Qt Creator!
How can I bring them in qtcreator?
PS: I don't wanna forget about the solution and install SDK.
I know OP asked for archlinux but I faced the same issue with Ubuntu 20.04. To solve it I had to install the following two packages:
sudo apt-get install qtbase5-examples qtbase5-doc-html
This will show the basic widget examples.
Additional examples (e.g. qt quick) can be added by installing them explicitly:
sudo apt install qtquickcontrols2-5-examples
To actually get them displayed in qtcreator I had to install:
sudo apt install qt5-doc qt5-doc-html
Here is the output of echo $(apt-mark showmanual | grep -P '(libqt|qt)')
cmake-qt-gui qt5-default qt5-doc qt5-doc-html qtbase5-dev qtbase5-doc-html qtbase5-examples qtcreator qtquickcontrols2-5-examples
Edit:
Also make sure to install the qml modules you need, for example:
sudo apt install qml-module-qtquick-controls2
QtCreator Examples are added in Official Repository 'Extra'
https://www.archlinux.org/packages/extra/any/qt5-examples/
install it using :-
sudo pacman -S qt5-examples
Navigate to the installation location of the examples and open the .pro project file with qt-creator.
Alternatively if you just want to build and run the example. Navigate to the directory qmake and then make and then simple run the output
Additionally if you strictly require the examples to show in the IDE, try launching with admin privileges as the installation directory of the examples may require admin privileges.
My situation is that qt example folder has no permission to read and execute for non-root users, fixed it and everything OK. In your case:
sudo chmod +rx /usr/share/doc/qt/examples
I am also using archlinux and have had the same problem. Despite not having the examples & demo installed the qmake-qt5 -query is printing a non-existence path.
It seems Qt5 examples are now on AUR(Arch User Repository).
To get the them
Download https://aur.archlinux.org/packages/qt/qt5-examples/qt5-examples.tar.gz
Extract the package maybe with $ tar xzf qt5-examples.tar.gz
cd qt5-examples which contains the PKGBUILD . Then run makepkg .This will download 165MB qt-everywhere-opensource-src-5.2.0.tar.xz
Run pacman -U qt-everywhere-opensource-src-5.2.0.tar.xz
Qtcreator cannot detect the example without its html file.
So, in my case I've already installed qtbase5-examples, but could not able to see examples in qtcreator.
After,
sudo apt-get install qtbase5-doc-html
examples are visible in qtcreator. It was the same with qt5serialport-examples.
sudo apt-get install qt5serialport-examples qtserialport5-doc-html
Have a nice one.
make sure you run the qt-opensource-linux-x86-android-5.4.0.run like this:
$sudo ./qt-opensource-linux-x86-android-5.4.0.run
please do not forget the "sudo"
or you will find that the examples in the qtcreator is missing.

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