MySQL driver detected but not loading on MacOS

[Vince2480]

Hi, hope someone can answer this....

I am trying to upgrade a MacOS desktop app I wrote back then under ver. 5.4. Surprisingly, that app is working still, even on Big Sur. My original Qt IDE installation has got damaged so I had to download a new one. I am using Desktop 5.9.9 clang 64, installed using the maintenance tool I downloaded.

The libmysql plugins were included, so I assume they should just work, but for whatever reason, they're not loading.

At this time, the compiler is giving me hundreds of warning messages of deprecated classes (definition of copy constructor and assignment) which I'm ignoring for now until I get the driver loaded. I don't know if this is impacting the sql connection strings I'm passing to QsqlDatabase.

When I run the app, a message box comes up with
! Driver not loaded Driver not loaded.

I set some debug output to see if indeed it was detected and what path.

Library path:
("/Users/[USER]/Qt/5.9.9/clang_64/plugins", "/Users/[USER]/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS")
Drivers:
("QSQLITE", "QMYSQL", "QMYSQL3", "QPSQL", "QPSQL7")
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

I don't understand why the driver won't load.
The app I built on Qt 5.4 DOES work using the driver that is installed in the Qt 5.4 directory. I did try to copy that driver into 5.9 but the version was not compatible.
Can anyone help please?

[jsulm]

@Vince2480 Set QT_DEBUG_PLUGINS before starting your app and check the output (you can also post it here). See https://doc.qt.io/qt-5/debug.html
You should also use search function in this forum as exact same question is asked very often.

[Vince2480]

@jsulm said in MySQL driver detected but not loading on MacOS:

QT_DEBUG_PLUGINS

Thanks jsulum for your response,
QT_DEBUG_PLUGINS=1 has already been set in the .pro file and the output printed in the last 2 lines in my post...

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

and I've searched the same question on this and other forums and haven't found any answers.

[artwaw]

@Vince2480 The next logical step would be to make sure that mysql lib is on the library path when the program runs.

[Christian Ehrlicher]

@Vince2480 said in MySQL driver detected but not loading on MacOS:

QT_DEBUG_PLUGINS=1 has already been set in the .pro

What should this help? QT_DEBUG_PLUGINS is an environment variable...

[jsulm]

@Vince2480 said in MySQL driver detected but not loading on MacOS:

QT_DEBUG_PLUGINS=1 has already been set in the .pro

You don't set it in the pro file, you set it in terminal where you run the app or in Run settings of your project...

[Vince2480]

artwaw, you mean the Qt plugins? because I have confirmed the app is attempting to load the plugins, unsuccessfully.

jsulm, OK, I didn't know that, can I set that in Qt Creator IDE?

[jsulm]

@Vince2480 said in MySQL driver detected but not loading on MacOS:

can I set that in Qt Creator IDE?

Yes, as mentioned in Run settings (Environment) - add QT_DEBUG_PLUGINS environment variable there with value 1

[Vince2480]

Thanks jsulm, I can see now it's looking for the files in /usr/local/mysql/lib that doesn't exist!

[jsulm]

@Vince2480 said in MySQL driver detected but not loading on MacOS:

/usr/local/mysql/lib

Can you post whole output?

[Vince2480]

@jsulm
19:18:00: Starting /Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/VDB ...
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqcocoa.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqcocoa.dylib, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"cocoa"
]
},
"className": "QCocoaIntegrationPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("cocoa")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqminimal.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqminimal.dylib, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimal"
]
},
"className": "QMinimalIntegrationPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqminimal_debug.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqminimal_debug.dylib, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"minimal"
]
},
"className": "QMinimalIntegrationPlugin",
"debug": true,
"version": 329993
}

Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqoffscreen.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqoffscreen.dylib, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"offscreen"
]
},
"className": "QOffscreenIntegrationPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqoffscreen_debug.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqoffscreen_debug.dylib, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData": {
"Keys": [
"offscreen"
]
},
"className": "QOffscreenIntegrationPlugin",
"debug": true,
"version": 329993
}

Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/platforms" ...
loaded library "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqcocoa.dylib"
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platformthemes" ...
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/platformthemes" ...
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/styles" ...
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/styles" ...
loaded library "/System/Library/Frameworks/Carbon.framework/Carbon"
Library path:
("/Users/vinceieraci/Qt/5.9.9/clang_64/plugins", "/Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS")
Drivers:
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers" ...
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlite.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlite.dylib, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QSQLITE"
]
},
"className": "QSQLiteDriverPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("QSQLITE")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlite_debug.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlite_debug.dylib, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QSQLITE"
]
},
"className": "QSQLiteDriverPlugin",
"debug": true,
"version": 329993
}

Got keys from plugin meta data ("QSQLITE")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QMYSQL3",
"QMYSQL"
]
},
"className": "QMYSQLDriverPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("QMYSQL3", "QMYSQL")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql_debug.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql_debug.dylib, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QMYSQL3",
"QMYSQL"
]
},
"className": "QMYSQLDriverPlugin",
"debug": true,
"version": 329993
}

Got keys from plugin meta data ("QMYSQL3", "QMYSQL")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlpsql.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlpsql.dylib, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QPSQL7",
"QPSQL"
]
},
"className": "QPSQLDriverPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("QPSQL7", "QPSQL")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlpsql_debug.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlpsql_debug.dylib, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QPSQL7",
"QPSQL"
]
},
"className": "QPSQLDriverPlugin",
"debug": true,
"version": 329993
}

Got keys from plugin meta data ("QPSQL7", "QPSQL")
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/sqldrivers" ...
("QSQLITE", "QMYSQL", "QMYSQL3", "QPSQL", "QPSQL7")
Cannot load library /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
Referenced from: /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
Reason: image not found)
QLibraryPrivate::loadPlugin failed on "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n Referenced from: /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n Reason: image not found)"
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
db.open() next...:
db.open() ok:
lasterr().type() 1 title "Connection Error 1" text "Driver not loaded Driver not loaded"
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/iconengines" ...
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/iconengines/libqsvgicon.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/iconengines/libqsvgicon.dylib, metadata=
{
"IID": "org.qt-project.Qt.QIconEngineFactoryInterface",
"MetaData": {
"Keys": [
"svg",
"svgz",
"svg.gz"
]
},
"className": "QSvgIconPlugin",
"debug": false,
"version": 329993
}

Got keys from plugin meta data ("svg", "svgz", "svg.gz")
QFactoryLoader::QFactoryLoader() looking at "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/iconengines/libqsvgicon_debug.dylib"
Found metadata in lib /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/iconengines/libqsvgicon_debug.dylib, metadata=
{
"IID": "org.qt-project.Qt.QIconEngineFactoryInterface",
"MetaData": {
"Keys": [
"svg",
"svgz",
"svg.gz"
]
},
"className": "QSvgIconPlugin",
"debug": true,
"version": 329993
}

Got keys from plugin meta data ("svg", "svgz", "svg.gz")
QFactoryLoader::QFactoryLoader() checking directory path "/Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/iconengines" ...
QLibraryPrivate::unload succeeded on "/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/platforms/libqcocoa.dylib"
QLibraryPrivate::unload succeeded on "/System/Library/Frameworks/Carbon.framework/Carbon"
19:18:04: /Users/vinceieraci/Developer/build-VDB-Desktop_Qt_5_9_9_clang_64bit-Debug/VDB.app/Contents/MacOS/VDB exited with code 1

[jsulm]

@Vince2480 You could try to set LD_LIBRARY_PATH to point to folder containing libmysqlclient.20.dylib

[Vince2480]

@jsulm libmysqlclient.20.dylib is not on my system so does that means I need to install MySQL? I didn't do that for Qt5.4, has something changed between then and now?

[jsulm]

@Vince2480 said in MySQL driver detected but not loading on MacOS:

install MySQL?

Not the server, only client.

"has something changed between then and now?" - yes, the MySQL license has changed (since Oracle owns MySQL). Because of that QtCompany does not include MySQL client lib anymore in the Qt builds it's providing.

[Vince2480]

@jsulm OK, I see.

I installed

brew install mysql-client

only libmysqlclient.21.dylib so I linked with libmysqlclient.20.dylib
but it's the wrong architecture.

Cannot load library /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
  Referenced from: /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
  Reason: no suitable image found.  Did find:
	/opt/homebrew/Cellar/mysql-client/8.0.26/lib/libmysqlclient.20.dylib: mach-o, but wrong architecture
	/opt/homebrew/Cellar/mysql-client/8.0.26/lib/libmysqlclient.20.dylib: mach-o, but wrong architecture)

I downloaded mysql-connector-c++ but that doesn't look viable.
Where do I find the required files?

[jsulm]

@Vince2480 What does

file /opt/homebrew/Cellar/mysql-client/8.0.26/lib/libmysqlclient.20.dylib

and

file /Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib

output?

[Vince2480]

@jsulm Excuse my ignorance, I don't understand the question.

[JonB]

@Vince2480
From a command prompt/terminal/shell, copy & paste exactly each of the two lines @jsulm typed, and paste back here what response you get.

[Vince2480]

@JonB

/opt/homebrew/Cellar/mysql-client/8.0.26/lib/libmysqlclient.20.dylib: Mach-O 64-bit dynamically linked shared library

/Users/vinceieraci/Qt/5.9.9/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: Mach-O 64-bit dynamically linked shared library x86_64

[jsulm]

@Vince2480 Both seems to be 64bit libs, except that libmysqlclient.20.dylib is missing x86_64.
Do you by any chance use a M1 Mac?