Snap with qt methods of QDir

EndrII 0

This post is a duplicate of the Snapcraft Developer Forum.

Now I am engaged in the assembly of my application in a snap and I encountered an unexpected problem.
The following qt functions do not work in an application that is started from the snap rollback:

To prove this, I give an example:

There is a function that parses application settings

bool parseQt(Deploy &deploy) {

    auto bin = QuasarAppUtils::Params::getStrArg("bin");

    QFileInfo info(bin);
    if (!info.exists()) {
        verboseLog(QDir::homePath());
        verboseLog(QDir("./").absolutePath());

        verboseLog("bin file is not file path: " + bin);
        return false;
    }

    if (!deploy.setTarget(bin)) {
        qCritical() << "error init targeet dir";
        return false;
    }

    int limit = 0;

    if (QuasarAppUtils::Params::isEndable("recursiveDepth")) {
        bool ok;
        limit = QuasarAppUtils::Params::getArg("recursiveDepth").toInt(&ok);
        if (!ok) {
            limit = 0;
            qWarning() << "recursiveDepth is invalid! use default value 0";
        }
    }

    deploy.setDepchLimit(limit);

    if (QuasarAppUtils::Params::isEndable("clear")) {
        qInfo() << "clear old data";
        deploy.clear();
    }

    auto listLibDir = QuasarAppUtils::Params::getStrArg("libDir").split(",");
    auto listExtraPlugin =
        QuasarAppUtils::Params::getStrArg("extraPlugin").split(",");
    deploy.setExtraPath(listLibDir);
    deploy.setExtraPlugins(listExtraPlugin);

    if (!deploy.initDirs()) {
        qCritical() << "error init targeet dir";
        return false;
    }

    auto qmake = QuasarAppUtils::Params::getStrArg("qmake");
    QString basePath = "";
    info.setFile(qmake);

    verboseLog("qmake path =" + qmake);
    verboseLog("qmake path from info =" + info.absoluteFilePath());
    verboseLog("qmake baseName from info =" + info.baseName());

    if (!info.exists() || (info.baseName() != "qmake")) {
        qInfo() << "deploy only C libs because qmake is not found";
        deploy.setOnlyCLibs(true);
        return true;
    }

    basePath = info.absolutePath();
    deploy.setQmake(qmake);
    auto scaner = basePath + QDir::separator() + "qmlimportscanner";

    auto qmlDir = QuasarAppUtils::Params::getStrArg("qmlDir");

    QDir dir(basePath);

    verboseLog("basePath =" + basePath);
    verboseLog("qmlDir =" + qmlDir);
    verboseLog("scaner =" + scaner);

    if (QFileInfo::exists(qmlDir) && QFileInfo::exists(scaner)) {

        deploy.setDeployQml(true);
        deploy.setQmlScaner(scaner);

    } else if (QuasarAppUtils::Params::isEndable("allQmlDependes")) {
        deploy.setDeployQml(true);
    } else {
        qWarning() << "wrong qml dir!, deploy qml skiped!";
    }

    if (!dir.cdUp()) {
        auto path =  basePath.left(basePath.lastIndexOf("/"));
        verboseLog("parrent dir no exits! path dir =" + path);

        verboseLog("parrent dir no exits! this dir =" +
                   QString((dir.cd(path))? "true": "false"));

        verboseLog("parrent dir no exits! this dir =" + dir.path());
        return false;
    }

    deploy.setQtDir(dir.absolutePath());

    return true;
}

And there is a log of this function (provided after launching the application from the snap package)

endrii@Xenon:~/linuxdeployqt$ cqtdeployer -bin EXOSTAR_Editor -qmake $PWD/gcc_64/bin/qmake verbose clear
realpath: '': No such file or directory
realpath: '': No such file or directory
realpath: '': No such file or directory
realpath: '': No such file or directory
realpath: '': No such file or directory
realpath: '': No such file or directory
realpath: '': No such file or directory
realpath: '': No such file or directory
clear old data
Empty filename passed to function
""  does not exist! and skiped
Empty filename passed to function
""  does not exist! and skiped
"qmake path =/home/endrii/linuxdeployqt/gcc_64/bin/qmake"
"qmake path from info =/home/endrii/linuxdeployqt/gcc_64/bin/qmake"
"qmake baseName from info =qmake"
get qml fail!
"basePath =/home/endrii/linuxdeployqt/gcc_64/bin"
"qmlDir ="
"scaner =/home/endrii/linuxdeployqt/gcc_64/bin/qmlimportscanner"
Empty filename passed to function
wrong qml dir!, deploy qml skiped!
"parrent dir no exits! path dir =/home/endrii/linuxdeployqt/gcc_64"
"parrent dir no exits! this dir =false"
"parrent dir no exits! this dir =/home/endrii/linuxdeployqt/gcc_64/bin"
qt parse error

Usage: cqtdeployer <-bin    [params]> [options]

Options:
   help / h                 : show help.
   always-overwrite         : Copy files even if the target file exists.
   -bin    [params]         : deployment binry.
   -qmlDir [params]         : qml datadir of project. for example -qmlDir ~/my/project/qml
   deploy-not-qt            : deploy all libs
   -qmake  [params]         : qmake path. for example
                            | -qmake ~/Qt/5.11.1/gcc_64/bin/qmake
   -ignore [list,params]    : ignore filter for libs
                            | for example -ignore libicudata.so.56,libicudata2.so.56
   clear                    : delete all old deploy data
   -runScript [params]      : set new name of out file (AppRun.sh by default)
                            | for example -runScript myApp.sh
   allQmlDependes           : This flag will force to extract all qml libraries.
                            | (not recommended, as it takes up a lot of memory)
   -libDir [list,params]    : set additional path for extralib of app.
                            | for example -libDir ~/myLib,~/newLibs
   -extraPlugin[list,params]: set additional path for extraPlugin of app
   -recursiveDepth [params] : set Depth for recursive search of libs (default 0)
   verbose                  : show debug log

Example: cqtdeployer -bin myApp -qmlDir ~/Qt/5.11.1/gcc_64/qml -qmake ~/Qt/5.11.1/gcc_64/bin/qmake clear
Example (only C libs): cqtdeployer -bin myApp clear

The application has read and write access to the entire contents of the home directory.
Here is the contents of the linuxdeployqt folder:

endrii@Xenon:~/linuxdeployqt$ ls
.
├── EXOSTAR_Editor
└── gcc_64
    ├── bin
    ├── doc
    ├── include
    ├── lib
    ├── libexec
    ├── mkspecs
    ├── phrasebooks
    ├── plugins
    ├── qml
    ├── qtvirtualkeyboard
    ├── resources
    └── translations

13 directories, 1 file

endrii@Xenon:~/linuxdeployqt/gcc_64/bin$ ls
assistant         licheck64  pixeltool             qdbusxml2cpp    qlalr        qmlimportscanner  qmlscene               qtdiag            qwebengine_convert_dict  uic
canbusutil        linguist   qcollectiongenerator  qdoc            qmake        qmllint           qmltestrunner          qtpaths           rcc                      xmlpatterns
designer          lrelease   qdbus                 qgltf           qml          qmlmin            qscxmlc                qtplugininfo      repc                     xmlpatternsvalidator
fixqt4headers.pl  lupdate    qdbuscpp2xml          qhelpconverter  qmlcachegen  qmlplugindump     qtattributionsscanner  qtwaylandscanner  sdpscanner
lconvert          moc        qdbusviewer           qhelpgenerator  qmleasing    qmlprofiler       qt.conf                qvkgen            syncqt.pl

Please pay attention to this part of the code:

    if (!dir.cdUp()) {
        auto path =  basePath.left(basePath.lastIndexOf("/"));
        verboseLog("parrent dir no exits! path dir =" + path);

        verboseLog("parrent dir no exits! this dir =" +
                   QString((dir.cd(path))? "true": "false"));

        verboseLog("parrent dir no exits! this dir =" + dir.path());
        return false;
    }

And this part of the log:

"basePath =/home/endrii/linuxdeployqt/gcc_64/bin"
"qmlDir ="
"scaner =/home/endrii/linuxdeployqt/gcc_64/bin/qmlimportscanner"
Empty filename passed to function
wrong qml dir!, deploy qml skiped!
"parrent dir no exits! path dir =/home/endrii/linuxdeployqt/gcc_64"
"parrent dir no exits! this dir =false"
"parrent dir no exits! this dir =/home/endrii/linuxdeployqt/gcc_64/bin"

Here you can see how the cdUp method and manual launch of cd in the directory to the level above did not work as it should. At the same time access to the directory is.

I really need your help in solving this problem.

P.S.

version of qt : 5.11.2
version snapcraft: 2.43.1