don't install Qt by default, require pyside6 to be <6.7, check pyside…

… availability on editor launch

debug.py

@@ -25,6 +25,6 @@
             f"{RYVEN_PATH}/ryven/example_nodes/std",
             f"{RYVEN_PATH}/ryven/example_nodes/linalg",
         ],
-        qt_api='pyside2',
+        qt_api='pyside6',
         show_dialog=False,
     )

ryven-editor/ryven/main/Ryven.py

@@ -7,6 +7,32 @@
 from ryven.main.args_parser import process_args
 
 
+def check_pyside_available(qt_api: str):
+    if qt_api == 'pyside2':
+        try:
+            import PySide2
+        except ImportError:
+            sys.exit(
+                'You are trying to use PySide2 as the Qt API, but it is not available. '
+                'please install it, or use pyside6 as the Qt API. Either of those can '
+                'installed through pip, e.g. `pip install pyside2` or `pip install \'pyside6<6.7\'`. '
+            )
+    elif qt_api == 'pyside6':
+        try:
+            import PySide6
+        except ImportError:
+            sys.exit(
+                'You are trying to use PySide6 as the Qt API, but it is not available. '
+                'please install it, or use pyside2 as the Qt API. Either of those can '
+                'installed through pip, e.g. `pip install pyside2` or `pip install \'pyside6<6.7\'`. '
+            )
+    else:
+        sys.exit(
+            f'Error: Illegal Qt API: "{qt_api}". '
+            f'Use either "pyside2" or "pyside6". '
+        )
+
+
 def run(*args_,
         qt_app=None, gui_parent=None, use_sysargs=True,
         **kwargs):
@@ -72,6 +98,7 @@ def run(*args_,
     #
 
     # Init environment
+    check_pyside_available(conf.qt_api)
     os.environ['RYVEN_MODE'] = 'gui'
     os.environ['QT_API'] = conf.qt_api
     from ryven.node_env import init_node_env

ryven-editor/setup.cfg

@@ -27,6 +27,11 @@ install_requires =
     Pygments
     textdistance
     packaging
+extras_require = 
+    PySide2 =
+        PySide2
+    PySide6 =
+        PySide6 = <6.7
 
 [options.entry_points]
 console_scripts =

ryvencore-qt/setup.cfg

@@ -21,7 +21,6 @@ include_package_data = True
 python_requires = >=3.6, <3.11
 install_requires =
     ryvencore ==0.4.*
-    PySide2
     QtPy
     waiting
     textdistance