qt.core.qobject.connect: QObject::connect: signal not found

[Deema35]

qBittorrent & operating system versions

qBittorrent:4.4.0rc1
Operating system:Linux
Qt:6.2.1
libtorrent-rasterbar: 2.0.4

What is the problem?

Hi. I had build qBittorrent for OpenWRT. But after I am start qBittorrent I have got errors:

qt.core.qobject.connect: QObject::connect: signal not found in QLocalServer
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in Application
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in QNetworkAccessMan                                                                                                                                                             ager
qt.core.qobject.connect: QObject::connect: signal not found in QNetworkAccessMan                                                                                                                                                             ager
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in QThread
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in DownloadHandlerIm                                                                                                                                                             pl
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No TLS backend is available
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No TLS backend is available
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.core.qobject.connect: QObject::connect: signal not found in QHttpThreadDelega                                                                                                                                                             te
qt.core.qobject.connect: QObject::connect: signal not found in QNetworkReplyHttp                                                                                                                                                             Impl
qt.core.qobject.connect: QObject::connect: signal not found in QFileSystemWatche                                                                                                                                                             r
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in Application
qt.core.qobject.connect: QObject::connect: signal not found in Application
qt.core.qobject.connect: QObject::connect: signal not found in QThread
qt.network.ssl: No functional TLS backend was found
qt.core.qobject.connect: QObject::connect: signal not found in Application
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.network.ssl: No functional TLS backend was found
qt.core.qobject.connect: QObject::connect: signal not found in QThread
qt.core.qobject.connect: QObject::connect: signal not found in QThread
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in QThread
qt.core.qobject.connect: QObject::connect: signal not found in QTimer

******** Information ********
To control qBittorrent, access the Web UI at http://localhost:8080
The Web UI administrator username is: admin
The Web UI administrator password has not been changed from the default: adminad                                                                                                                                                             min
This is a security risk, please change your password in program preferences.
qt.core.qobject.connect: QObject::connect: signal not found in QThread
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No TLS backend is available
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: No TLS backend is available
qt.network.ssl: No functional TLS backend was found
qt.network.ssl: QSslSocket::connectToHostEncrypted: TLS initialization failed

I can see qBittorrent process from htop. But I can't get access to Web UI.
I build qBittorrent by using cmake ad qt6 by cmake too (#15697 (comment)).

Steps to reproduce

No response

Additional context

No response

Log(s) & preferences file(s)

No response

[abcfy2]

qt.network.ssl: No functional TLS backend was found means you does not link a ssl backend. E.g openssl or gnutls for Linux.

Did you forget install openssl or static link to openssl?

You can check the qt6 official doc for detail: https://doc.qt.io/qt-6/configure-options.html#ssl

Also you may refer to my script for cross compiling: https://github.com/c0re100/qBittorrent-Enhanced-Edition/blob/v4_4_x/.github/workflows/cross_build.sh

[Deema35]

I had set:
-DQT_FEATURE_openssl=ON
-DQT_FEATURE_openssl_linked=ON
This is cmake log:

Build options:
  Mode ................................... release
  Optimize release build for size ........ no
  optimize_full .......................... yes
  Building shared libraries .............. yes
  Using C standard ....................... C11
  Using C++ standard ..................... C++17
  Using ccache ........................... no
  Using new DTAGS ........................ yes
  Relocatable ............................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    Intrinsics without compiler architecture option  yes
    Extensions ........................... NEON CRC32
  Sanitizers:
    Addresses ............................ no
    Threads .............................. no
    Memory ............................... no
    Fuzzer (instrumentation only) ........ no
    Undefined ............................ no
  Build parts ............................ libs
Qt modules and options:
  concurrent ............................. no
  Qt D-Bus ............................... yes
  Qt D-Bus directly linked to libdbus .... no
  gui .................................... no
  Qt Network ............................. yes
  printsupport ........................... no
  Qt Sql ................................. yes
  testlib ................................ no
  widgets ................................ no
  Qt Xml ................................. yes
Support enabled for:
  Using pkg-config ....................... yes
  udev ................................... no
  Using system zlib ...................... yes
  zstd ................................... no
  Thread support ......................... yes
Common build options:
  Linker can resolve circular dependencies  yes
Qt Core:
  backtrace .............................. no
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... no
  ICU .................................... no
  Using system libb2 ..................... no
  Built-in copy of the MIME database ..... yes
  Tracing backend ........................ <none>
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  PCRE2 .................................. yes
  system_pcre2 ........................... no
  CLONE_PIDFD support in forkfd .......... yes
Qt Sql:
  SQL item models ........................ yes
Qt Network:
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  Linux AF_NETLINK ....................... yes
  openssl ................................ yes
  openssl_linked ......................... yes
  OpenSSL 1.1 ............................ yes
  DTLS ................................... no
  OCSP-stapling .......................... yes
  SCTP ................................... no
  Use system proxies ..................... yes
  GSSAPI ................................. no
  Brotli Decompression Support ........... no
Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... no
  PostgreSQL ............................. no
  SQLite ................................. yes
    Using system provided SQLite ......... no
Qt Tools:
  Qt Assistant ........................... no
  QDoc ................................... no
  Clang-based lupdate parser ............. no
  Qt Designer ............................ no
  Qt Distance Field Generator ............ no
  Qt Linguist ............................ yes
  Mac Deployment Tool .................... no
  pixeltool .............................. no
  qdbus .................................. yes
  Qt Attributions Scanner ................ yes
  qtdiag ................................. no
  qtplugininfo ........................... yes
  Windows deployment tool ................ no

But I have got same errors.

[Deema35]

And OpenSSL had installed on my router.

[Deema35]

I have same result even I have set flag static for qt6:
-DCMAKE_CXXFLAGS="-static"
-DCMAKE_LDFLAGS="-static"

[abcfy2]

Did you use cmake for cross compile environment ? I mean you have to set CMAKE_SYSTEM_NAME like -DCMAKE_SYSTEM_NAME=Linux, then cmake will consider you are in cross compile environment, otherwise cmake does not work in cross environment.

Thus when cmake running environment check will output like:

...
-- CMAKE_SYSTEM_PROCESSOR: "arm"
-- CMAKE_CROSSCOMPILING: "TRUE"
-- CMAKE_C_COMPILER: "/cross_root/bin/arm-linux-musleabihf-gcc" (10.2.1
...

Note CMAKE_CROSSCOMPILING must be TRUE, and also you have to cross compile openssl and make qtbase cross lib could link to openssl as well.

[Deema35]

CMAKE_SYSTEM_PROCESSOR: "arm"
CMAKE_CROSSCOMPILING: "TRUE"
same result.
CMAKE_C_COMPILER I dont try. Because if archetecture mismatching qbittorrent can't run. But it run only with errors.

[Deema35]

I create topic on qt forum: https://forum.qt.io/topic/131787/error-connect-signal-not-found-on-qt6-after-cross-compile

[Deema35]

On qt forum says that it issue because, of exist errors in qBittorrent. That they answer:

After a brief look into the source code if qBittorrrent: Starting with mainwindow.cpp there are a lot of connect statements in class constructors, the result of which is not read. The statements connecting slots/signals of Qt classes (eg QtabWidget in line 192 of mainwindow.cpp) look pretty fine. The majority of connects, however, handle internal signals and slots of qBittorrent. Having said that, the most likely scenario is that the source code uses Qt functionality that is still available in Qt 5 and no longer available as from version 6. Since aBittorrent seems to support Qt6 (looking at src.pro in the src subdue), you may want to file a bug report within the qBittorrent project.

[abcfy2]

Would you please try my build artifact in your environment qbittorrent-nox_aarch64-linux-musl_static.zip ? All dependencies are static linked.

Also you can copy my build script https://github.com/c0re100/qBittorrent-Enhanced-Edition/blob/v4_4_x/.github/workflows/cross_build.sh to .github/workwork/ and run docker run --rm -v `git rev-parse --show-toplevel`:/build -e CROSS_HOST=aarch64-linux-musl ubuntu:20.04 /build/.github/workflows/cross_build.sh yourself.

I don't know how you build qbittorent. You could share your build script here.

[Deema35]

Would you please try my build artifact in your environment qbittorrent-nox_aarch64-linux-musl_static.zip ? All dependencies are static linked.

Yes it's work fine.

I build qBittorrent with OpenWRT. This is my make file with guide how to build https://github.com/Deema35/qBittorrent-openwrt-package/tree/qt6

[breakings]

qBittorrent:4.4.0
Operating system:Linux arm64
Qt:6.2.2
libtorrent-rasterbar: 2.0.5

I also get this error:
qt.core.qobject.connect: QObject::connect: signal not found in QLocalServer
qt.core.qobject.connect: QObject::connect: signal not found in QTimer
qt.core.qobject.connect: QObject::connect: signal not found in Application

[Deema35]

I think this is because cmkae have not MOC (Meta-Object Compiler).

[breakings]

I see this when compile:
[251/384] Automatic MOC and UIC for target Network
qtbase-everywhere-src-6.2.2/src/network/access/qnetworkaccessdebugpipebackend_p.h:0:1: note: No relevant classes found. No output generated.