Building Qt 5.15.16 from source

Pouriya

I tried to build Qt 5.15.16 from source on Windows 10 with MinGW 8.1.0 64-bit.
after some time I get this error:

Is it a bug in Qt or in Mingw?

piervalli

The build with Mingw 8.1 works with 5.15.16
There was a post with binary 10 days ago.
https://bin.ceicer.com/qt/ . Probably there is missing requires.

SGaist

Hi,

Usually, when a compiler crashes, it means there's an issue with the compiler.

Pouriya

@SGaist Hi,
In this url it is mentioned that Qt 5.15 is compatible with Mingw 8.1.0:
https://wiki.qt.io/MinGW
If there is a bug in the compiler how the previous Qt binaries were built? like Qt 5.15.2 which was available in the online installer.

SGaist

You realise that between 5.15.2 and 5.15.16 there are 14 patch releases that have occurred ?
I don't know which version of MinGW is used to provide the commercial binaries but it's likely a more recent one.
You can check the bug report system to see if there's something related to such a crash.

Pouriya

@SGaist
Yes, I understand but I mean if the url says that mingw 8.1 is for qt 5.15, is it possible to become incompatible after some patches?

piervalli

The build with Mingw 8.1 works with 5.15.16
There was a post with binary 10 days ago.
https://bin.ceicer.com/qt/ . Probably there is missing requires.

piervalli

To build with Qt install Jenkins CI/CD, it saves all logs, some time errors should be before.

Pouriya

@piervalli Hi, thanks for your help. The openssl was missing.
Now I could build both x86 and x64 version of Qt with Mingw 8.1.
But there is a problem that I couldn't figure out.
When I call x64 version of windeployqt, it copies the libgcc_s_seh-1.dll, libstdc++-6.dll and libwinpthread-1.dll from 64-bit mingw folder which is ok, but when I call x86 version of windeployqt it copies the same mentioned libraries instead of 32-bit version of libgcc_s_dw2-1.dll, libstdc++-6.dll and libwinpthread-1.dll to the folder of .exe file.

Bonnie

@Pouriya From checking the source code of winployqt tool:

static QStringList compilerRunTimeLibs(const QString &qtBinDir, Platform platform, bool isDebug, unsigned short machineArch)
    {
        QStringList result;
        switch (platform) {
        case WindowsDesktopMinGW: {
            const QStringList minGWRuntimes = { "*gcc_"_L1, "*stdc++"_L1, "*winpthread"_L1 };
            result.append(findMinGWRuntimePaths(qtBinDir, platform, minGWRuntimes));
            break;
        }
    ......

static QStringList findMinGWRuntimePaths(const QString &qtBinDir, Platform platform, const QStringList &runtimeFilters)
{
    //MinGW: Add runtime libraries. Check first for the Qt binary directory, and default to path if nothing is found.
    QStringList result;
    const bool isClang = platform == WindowsDesktopClangMinGW;
    QStringList filters;
    const QString suffix = u'*' + sharedLibrarySuffix();
    for (const auto &minGWRuntime : runtimeFilters)
        filters.append(minGWRuntime + suffix);

    QFileInfoList dlls = QDir(qtBinDir).entryInfoList(filters, QDir::Files);
    if (dlls.isEmpty()) {
        std::wcerr << "Warning: Runtime libraries not found in Qt binary folder, defaulting to looking in path\n";
        const QString binaryPath = isClang ? findInPath("clang++.exe"_L1) : findInPath("g++.exe"_L1);
        if (binaryPath.isEmpty()) {
            std::wcerr << "Warning: Cannot find " << (isClang ? "Clang" : "GCC") << " installation directory, " << (isClang ? "clang++" : "g++") << ".exe must be in the path\n";
            return {};
        }
        const QString binaryFolder = QFileInfo(binaryPath).absolutePath();
        dlls = QDir(binaryFolder).entryInfoList(filters, QDir::Files);
    }

    for (const QFileInfo &dllFi : dlls)
        result.append(dllFi.absoluteFilePath());

    return result;
}

So it just searches for filename matches "*gcc_*.dll" from qt bin folder (or the PATH), not from corresponding mingw folder.

piervalli

Removed mingw32 from path is not necessary to build with Qt.

create a file deploy64.bat
PATH=%PATH%;C:\Qt\Tools\mingw810_64\bin

end the corrisponding for 32bit
create a file deploy32.bat
PATH=%PATH%;C:\Qt\Tools\mingw810_..