Description of problem:
When using the shiboken2 generator, setting any debug level with --debug-level=(sparse|medium|full) shows no effect.


Version-Release number of selected component (if applicable):
shiboken2-1:5.13.2-1.fc31.x86_64


How reproducible:
100%


Steps to Reproduce:
1. Download the pyside2-Repo with git clone git://code.qt.io/pyside/pyside-setup
2. Navigate to the samplebindings example: cd pyside-setup/examples/samplebinding
3. Execute shiboken2
shiboken2 --debug-level=full --generator-set=shiboken --enable-parent-ctor-heuristic --enable-return-value-heuristic --use-isnull-as-nb_nonzero --avoid-protected-hack -I$(pwd)  -T$(pwd) bindings.h bindings.xml

Actual results:

[momo@momolaptop samplebinding]$ shiboken2 --generator-set=shiboken --enable-parent-ctor-heuristic --enable-return-value-heuristic --use-isnull-as-nb_nonzero --avoid-protected-hack -I$(pwd)  -T$(pwd) bindings.h bindings.xml
(bindings)  [263ms] Generating class model (10)...                              [OK]
(bindings)  [263ms] Generating enum model (0)...                                [OK]
(bindings)  [263ms] Generating namespace model (0)...                           [OK]
(bindings)  [263ms] Resolving typedefs (65)...                                  [OK]
(bindings)  [263ms] Fixing class inheritance...                                 [OK]
(bindings)  [263ms] Detecting inconsistencies in class model...                 [OK]
(bindings)  [263ms] Detecting inconsistencies in typesystem (6)...              [OK]
(bindings)  [263ms] Checking inconsistencies in function modifications...       [OK]
(bindings)  [263ms] Writing log files...                                        [OK]
(bindings)  [264ms] Running Source generator...                                 [OK]
(bindings)  [266ms] Running Header generator...                                 [OK]


Expected results:

More debug information mixed into output, e.g. this block:
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "clone()" for Icecream: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "~Icecream()" for Icecream: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "getFlavor()" for Icecream: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "Truck(bool)" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "Truck(const Truck&)" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "operator=(const Truck&)" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "~Truck()" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "addIcecreamFlavor(Icecream*)" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "printAvailableFlavors()" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "deliver()" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "arrive()" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "leave()" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "setLeaveOnDestruction(bool)" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "setArrivalMessage(const std::string&)" for Truck: false
qt.shiboken: (bindings) traverseFunction: Checking rejection for signature "clearFlavors()" for Truck: false


Additional info:
While building the shiboken2-generator myself I noticed that the problem vanishes when replacing all occurences of qCDebug by qCWarning in the code. The reason for this is probably explained here: https://community.kde.org/Guidelines_and_HOWTOs/Debugging/Using_Error_Messages
It is stated that since Qt5.2 all debug lines are deactivated by default. Indeed, adding 
QLoggingCategory::setFilterRules(QStringLiteral("*.debug = true"));
to the main function solves this issue.