Basically, I wrote a program using Go and the binding for the Qt gui library (github.com/bluszcz/cutego). I moved over to the cutego fork because the original binding (github.com/therecipe/qt) isn't being maintained anymore.
My app works great but I need it to run on a machine that needs nothing installed. I'm new to Go so please forgive my ignorance. I followed the instructions to build a static executable here: (https://github.com/therecipe/qt/wiki/Deploying-Windows-to-Windows-64-bit-Static)
I get a few deprecated code warnings but the code does compile. The problem is I still end up with a dynamically compiled executable. I ran ldd using MINGW64 and I get:
Qt5Core.dll => not found
Qt5Gui.dll => not found
Qt5Widgets.dll => not found
As mentioned I am pretty new to Go, but I am also new to this kind of language as I have only developed using Python and VBA. I haven't found any clues online, I think because there's something really obvious that I am missing that everyone else knows about already.
What am I missing here? Any help would be most appreciated!
I would like my executable to be statically typed so that it can run without Qt installed.
When you use cgo, your go executable will link to shared libraries at run time depending on what C libraries the cgo code references.
If you wish to use cgo and have a stand alone executable you need to link your binary to static libraries (typically .a files). It is up to the third party module to provide such libraries, though, and qt may not provide them out of the box.
I found the problem. So with github.com/therecipe/qt you have 2 install options. You can either install the normal default way or you can install using the "static" method. You'll have problems if you do both. I ended up removing all files relative to github.com/therecipe/qt. I then installed using the static Windows x64 to Windows x64 method ONLY and followed those instructions for deploying a static executable. Worked like a charm using the instructions for MYSYS2.
Related
I've attempted to follow the instructions on deploying Qt to Windows, but I am stuck on step number 1. In it, it tells you to:
cd C:\path\to\Qt
configure -static any other options you need
Unfortunately, I can't get the Qt DOS prompt to recognize the "configure" command despite attempting to use it in virtually every folder under my Qt installation. Does anyone know where this command is store? Everything else about my project is working great with Visual Studio, but I just can't seem to figure out the deployment.
I've Googled the crap out of this and tried both the Qt and the regular Windows command prompts. Any help would be greatly appreciated!
Thanks
EDIT: For clarity, I have tried dragging all of the .dlls needed to run my program (by running it and finding the ones I get errors on), but all that happens is I stop getting errors when trying to run my app. If I double click it with the .dlls in the same folder, nothing happens at all.
Are you sure you need the static Qt build? Note that you must static build the actual Qt framework for that, and only after that you can build your application.
If yes, make sure you have the Qt source code, because configure is part of the source code of Qt, it's a tool that configure the Qt build.
The step refers to path of Qt Source directory e.g. C:\QtSDK\QtSources\\
As you can see in qt5 source tree there is a file configure.bat
You need to run that with static option, so it will configure Qt for static linking.
Then you need to re-build Qt to make your new configuration to take effect.
Guys I've written app in qt and when trying to run it (double click on *.exe) I'm getting error that this application cannot start because qtnetwork4.dll isn't available. I've searched my drive and I found few files with this name (and copied one by one every time trying to run my app) but none of them seems to work. How can I solve it?
place into your *.exe - folder appropriate dll-s from %QT_PATH%\bin\
There is an app called Dependency Walker that will let you know what functions in qtnetwork4.dll are being used in your program. It can be found at the following:
http://www.dependencywalker.com/
All of the DLLs your program use will be from the same installation as the qmake.exe that is used to compile the program. If you are using Qt Creator you can see where the qmake.exe your using is located by going to:
tools->options->Qt4
Get the DLLs that are located at the path displayed here to make sure they will work with your program.
On windows, DLL are looked for in folder where executable lies, then using "PATH" environenment variable.
In your case, you want to put your dll along your executable, taking them from the sdk you're using to compile
The following page provides a lot of additional information on the subject (example, plugins, strategy for building installers)
To force using QtNetwork and linking it, you have to put
QT += network
in your poject file.
If you're sure you're not using it, you can use
QT -= network
I'm trying to access a MySql database from a Qt application but I get the following error:
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QSQLITE2
I find this very strange cause I have libqsqlmysql.so on my Qt folder. I have even tried to compile the MySql driver as a static plugin and add it to my .pro file as:
QTPLUGIN += qsqlmysql
But this also generates the same runtime error (it must've found the plugin cause there's no error compiling the application)
What am I missing? I would like to avoid having to compile Qt from source cause this will have to work seamlessly on the deploy machines as well.
BTW: Even though I'm developing and testing on Linux I will need to support Windows. Will I experience this same issue on Windows? How can I compile and link the MySql driver in both Linux and Windows?
The solution:
After following #Sergey's recommendations I did an strace of the application redirecting the output to grep so I could search for 'mysql' and for my surprise the application wasn't looking for the plugin at QTDIR/plugins/sqldrivers where I had libqsqlmysql.so, it was looking at QTDIR/lib. After copying the plugin to the lib folder the MySql connection worked.
Try opening the shared library with dlopen() and see if it loads and if not, what dlerror() tells you. I always run into similar problems on Windows. LoadLibrary()/GetLastError() saved me numerous times (last time it was because of a wrong version of some libiconv/libintl DLL). Running ldd on the plugin may also help.
If dlopen() works fine, try to load the plugin with QPluginLoader. If it doesn't load, then check the buildkey of the plugin. I usually do it the dirty way by running strings on the plugin and then looking for strings like "buildkey" or "QT_PLUGIN_VERIFICATION_DATA". Just looking at the build key and around it may give you an idea. For example, you may realize that you have compiled your plugin in the release mode while your application is compiled in the debug mode. In such case the build key won't match and the plugin won't load. Everything in the build key must match your configuration. Note that the version and the build key are checked differently: the build key must match exactly (or match some black magic called QT_BUILD_KEY_COMPAT), but in the version only the major version must match exactly, the minor version must be the version of Qt the plugin was compiled with or later and the patch level is ignored. So if your plugin was compiled with Qt 4.x.y then it will work with Qt versions 4.z.* where z>=x. This actually makes sense.
If the build key looks okay (which is unlikely if you got to this point), you may wish to look at QLibraryPrivate::isPlugin() source code to figure out what's wrong, but that doesn't look like an easy task to me (although running this in a debugger may help).
If QPluginLoader does load the plugin, check if it is in the right directory and has correct permissions. If you still didn't solve the problem by this point, it's time to look at the SQL module source code that actually loads these plugins. But it is extremely unlikely. I ran into this problem many, many times and it was always either the library not loading or the build key not matching.
Another way to go after QPluginLoader loads the plugin successfully is to use strace to figure out whether the program at least tries to open the plugin file. Searching for something like "sqldrivers" or "plugins" in the strace output should also give away the directory where Qt is searching for its plugins and specifically SQL drivers.
Update
Is it possible to compile the driver as a static plugin and don't worry about anything? Let's try:
d:\Qt4\src\plugins\sqldrivers\psql>qmake CONFIG+=static LIBS+=-Ld:/programs/Post
greSQL/lib INCLUDEPATH+=d:/programs/PostgreSQL/include
d:\Qt4\src\plugins\sqldrivers\psql>make
It compiles fine and now I got libqsqlpsql.a (release) and libqsqlpsqld.a (debug) in QTDIR/plugins/sqldrivers (it is the right place on Windows). I am using PostgreSQL driver here, but I don't think it will be any different for MySQL which I just don't have installed. Ok, let's compile some real program with it:
d:\alqualos\pr\archserv>qmake QTPLUGIN+=qsqlpsql PREFIX=d:/alqualos LIBS+=-Ld:/g
nu/lib INCLUDEPATH+=d:/gnu/include LIBS+=-Ld:/programs/PostgreSQL/lib LIBS+=-lpq
Note that I had to manually link to libpq, otherwise the linker would complain about undefined references. The funny thing is, qmake knows that qsqlpsql is located in QTDIR/plugins/sqldrivers and sets compiler and linker options accordingly. So it still needs to be in the right place to work, only you don't have to worry about your users running into the same problem as it is only used during compilation. An alternative would be to just use LIBS+=-Lpath/to/plugin LIBS+=-lqsqlpsql instead of QTPLUGIN+=qsqlpsql, at least the docs say that it should work, but I haven't tested it.
In order for the application to actually use the plugin I had to put the following in my main unit (CPP file):
#include <QtPlugin>
Q_IMPORT_PLUGIN(qsqlpsql)
It works! Also, from what I've been able to figure out from the sources, the build key and the version are checked only when a plugin is dynamically loaded (all the relevant stuff is in the QLibrary's private class, not even QPluginLoader's). So the resulting executable may (or may not, depending on the binary compatibility) work even with different versions and builds of Qt, although using it with older versions may trigger some bugs that were fixed later.
It is also worth noting that the order for loading SQL drivers is this: use the driver statically linked into Qt if available, then look for a driver registered manually with QSqlDatabase::registerSqlDriver(), then look for a driver statically imported into the application (the way described above), and finally try to load a shared plugin. So when you link statically, your users won't be able to use dynamically linked drivers they may already have, but will be able to use drivers linked statically into Qt (like in Ubuntu).
I compiled QT first and then realised that I need mysql as well. So I compiled mysql plugin by
executing following command in QT-DIR\src\plugins\sqldrivers\mysql folder.
Mysql plugin compile command
qmake "INCLUDEPATH+=$$quote(C:\Program Files\MySQL\MySQL Server 5.5\include)" "LIBS+=$$quote(C:\Program Files\MySQL\MySQL Server 5.5\lib\libmysql.lib)" mysql.pro
Plugings are then created in created in folder QT-DIR\plugins\sqldrivers.
However, when I tried to use it in my code. It failed with following error.
Error msg
QSqlDatabase: QMYSQLDriver driver not loaded
Solution
After some googling and checking Path variable I realised that the Mysql server lib
( C:\Program Files\MySQL\MySQL Server 5.5\lib) directory was not in my Path variable. I expect that the dll in this folder are used by the plugin at runtime. After including Mysql server lib in Path variable everything worked smoothly. Hope this information saves some hair on other programmers scalp, as I uprooted quite a few. :D
Last time I looked at this you needed to rebuild Qt from source and include the appropriate MySQL source.
Building Qt from the sources is not hard, it just takes a while. You are likely to have the required tools already.
A possible workaround may be to access the back-end over ODBC instead.
In order for your app to pick up the plugin at runtime, the shared library implementing the MySQL plugin needs to be placed in the correct directory. The best way of determining that directory is to check the output of QCoreApplication::libraryPaths. You can also force specific paths by using a qt.conf file.
Please note that plugins must be placed in subdirectories within the plugin path, and the final part of the path name (i.e., the parent directory of the shared libraries) cannot be changed. SQL drivers need to go in a directory named sqldrivers, i.e. <pluginpath>/sqldrivers. For more details on plugin directories, see How to Create Qt Plugins.
I was experiencing this same issue as well. I've been installing and experimenting with a lot of different Python tools and UIs. I then uninstalled everything python related. I did a fresh install of Python 3.2, PyQT 3.2, and Eric5. No more errors with the QMySQL driver.
well i have had this issue, and after a lot of time, and different tools, i found that QT ( on windows, have not been able to test on Linux.) loads the "QSQLMYSQL.." when requested, but before runtime the lib ("QSQLMYSQL..") file must reside on one of the searched paths (QApp.libraryPaths()) inside a folder called "sqldrivers".. otherwise QT will just ignore the file, even if it is at some other point inside the searched path.
what i did was to monitor the dependency of a sample app, and when i removed the "QSQLMYSQL.." dll from "plugins\sqldrivers\" it failed, but when i maded a folder inside the app folder, called "sqldrivers" and placed the "QSQLMYSQL..." inside there, it loaded.
what i have is mysql 5.5, qt 4.7.4.
hope anyone can use this, and if anyone knows more about it, i would like to know where to find it(http://doc.qt.nokia.com/stable/sql-driver.html, is the closest you can get to the information about the folder structur). :P
This may also happen if your QMYSQL plugin is linked against the "wrong" mysql_client.a or it isn't in the LD_LIBRARY_PATH. I had this problem on OSX because mysql was installed via ports, and I fixed it with:
install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient_r.18.dylib libqsqlmysql.dylib
I downloaded the qt embedded demo source code recently on my linux machine. Following are the outcomes during running of the program
I compiled it statically on my x86 machine and run the application on x86 machine it runs fine. But when i took the statically compiled binary file to other machine with Atom platform It run with some missing widgets. I found that the plugins cant be ported with static compilation. Can anybody tell me is it true? If no can anybody tell me the steps for it?
I compiled it dynamically with shared libraries. Then got an executalbe on linux. I did "ldd MyAppName". It show me the shared library files it is using. But I dont know how to package these. Can anybody tell me the steps to package it?
I checked in the article on deploying qt applications on X11-linux platforms. But its not complete. Can anybody give me the detailed steps?
Any help will be appreciated......
you either have a distro, that does'nt support atom, or libraries, that are not compiled with support for it. either way - something somewhere on your system (or your qt) is not compiled for atom
The problem is that you are compiling your app, and its libraries (static or dynamic) work for x86, not for Atom. Perhaps you are able to create some sort of fat binary (lipo?) so that pieces of your app will function on x86 and Atom, but bits using the x86-only libraries will not function on Atom. (Right? That's a concise definition of your problem?)
If you have the source code for the libraries that don't run on Atom, and they're important to you, you should consider porting the code to Atom. If it's open-source code, you can contribute to the project. While you didn't give many details, my (very generic) approach to this would be to get the code on an Atom machine, write a very short test application for the library, and work out the issues.
Re #2: There's little difference between compiling an app and linking to shared libraries or dynamic libraries. On your x86 machine, if you have this code (these "plugins") compiled as dynamic libraries, it's pretty much the same as statically linking those binaries into the app. These libraries will work on x86, whether they're dynamically or statically linked.
I'm not sure if that helps very much -- if you're getting binary Qt plugins as static or dynamic libraries without source, you're out of luck. Submit a bug report. If you have source code, you can do a lot more.
I just dynamically compiled my application and ported to atom platform. I found the dependencies and ported them also and set the environment variable LD_LIBRARY_PATH on target machine to my ported shared libraries and It worked. Thanks everybody for your suggestions
I have downloaded QT SDK LGLP (Creator + libraries) 4.6 and I am having problems compiling projects. After install I have added C:\Qt\2010.02\qt;C:\Qt\2010.02\qt\bin to PATH and added QTDIR env varaible containing C:\Qt\2010.02\qt, the I run "configure -platform win32-g++" to compile it. Everything went good.
I the tried to use QT Creator to create and compile a project.
The problem is everytime I try to compile I get the following error message:
No valid Qt version set. Set one in Tools/Options
Error while building project GUITest
When executing build step 'QMake'
Canceled build.
When I go to Tools/Options the manual version is set to v4.6.2, Location c:\qt\2010.02\qt\bin\qmake.exe. The auto detected version is set to even though I have added the dirs in Path. Is there something I am doing wrong here? Has anyone encountered this problem in Vista.
I have been working on this for 2 days, change configurations, reinstalled etc...
The QtDir value is compiled into the
qmake-binary. You can only change this
by recompiling qmake and passing on a
different value to qt-configure (I'm
not sure which setting or variable is
passed on to qmake) When using
precompiled, downloaded binaries,
you'll have to keep the QtDir at
c:\Qt\4.6.2
EDIT:
What I said was incorrect. The locations of qmake, moc,... are located in the file:
<Qt>/4.x.x/.qmake.cache
Try uninstalling/reinstalling qt creator
But i highly suspect you didnt compile qt properly as this problem seems really odd. I had alot of problems compiling so i know myself from the past mistakes.
Make sure you carefully reread install instructions for your environment, also if you have visual studio you need to follow procedure to install it in compliance with it. Same if you use another c compiler
If nothing goes right, the easiest way to install qt imo is directy from their git hub, chec installin qt from git, on their git site there is wiki that explains how to do it
its really easy and after that all you need to do is add the qt to creator
Hey, it QT emulators have lot of problems in vista, i have tried several times,it didnt work for me.. it works well with windows XP. though ill tell you in brief what you need to do
1)install latest perl
2)install carbide c++ editor
3)install Qt SDK
4)install s60 or N97 emulators
make sure that except perl all the items which are mentioned above will be in same drive,and also
make sure that folder names which you give while installation should not have spaces at all..
i.e suppose if you are going to place any of the above items in a folder whose name is having spaces it will not work.
if you have any doubts feel free to ask.