Compat: Check for successful GLEW initialisation fails on my PC / Trixie

I observed same strange behaviour already last year on my »Video Output« talk.
The return value indicates an unkown error, but the subsequent usage seemingly works...

On my Laptop, I don not see this error; it might be due to the very old graphics card on my PC...

FrOSCon26/FrOSCon.26.mm

@@ -115,6 +115,11 @@
 </node>
 <node CREATED="1785791092863" ID="ID_709044928" MODIFIED="1785791103479" TEXT="es ist viel Halbwissen unterwegs"/>
 </node>
+<node CREATED="1786698370507" ID="ID_716430210" MODIFIED="1786698395274" TEXT="Charakter des Vortrags">
+<node CREATED="1786698400516" ID="ID_284718896" MODIFIED="1786698416899" TEXT="mich selber interessieren die Hintergr&#xfc;nde und die Historie"/>
+<node CREATED="1786698417501" ID="ID_74513394" MODIFIED="1786698436512" TEXT="mu&#xdf; mich aber entscheiden, wo der Fokus liegen soll"/>
+<node CREATED="1786698441301" ID="ID_1640436512" MODIFIED="1786698454442" TEXT="es ist ein technischer Vortrag"/>
+</node>
 </node>
 <node CREATED="1715854555555" ID="ID_364372421" MODIFIED="1519335105159" TEXT="Fazit"/>
 </node>
@@ -1633,14 +1638,40 @@
 <node COLOR="#338800" CREATED="1754670469668" ID="ID_842741774" MODIFIED="1779389203289" STYLE="fork" TEXT="Template aus Vortrag FrOSCon 24">
 <icon BUILTIN="button_ok"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1754690553647" ID="ID_1097447180" MODIFIED="1779389203876" TEXT="Sllides anlegen">
+<node COLOR="#338800" CREATED="1754690553647" ID="ID_1097447180" MODIFIED="1786698315555" TEXT="Sllides anlegen">
-<icon BUILTIN="flag-yellow"/>
+<icon BUILTIN="button_ok"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1754790069195" ID="ID_532358745" MODIFIED="1779389203875" TEXT="Text ausarbeiten">
+<node COLOR="#338800" CREATED="1754790069195" ID="ID_532358745" MODIFIED="1786698317156" TEXT="Text ausarbeiten">
-<icon BUILTIN="flag-yellow"/>
+<icon BUILTIN="button_ok"/>
+</node>
+<node COLOR="#338800" CREATED="1754750859506" ID="ID_551478124" MODIFIED="1786698320272" TEXT="Animationen aufbauen">
+<icon BUILTIN="button_ok"/>
+</node>
+</node>
+<node CREATED="1786698500509" ID="ID_121807511" MODIFIED="1786698508055" TEXT="Vorbereitung auf den Vortag">
+<node CREATED="1786698511733" ID="ID_167244144" MODIFIED="1786698569122" TEXT="erste Probel&#xe4;ufe: die Zeit ist zu knapp "/>
+<node CREATED="1786698569659" ID="ID_943822780" MODIFIED="1786698608319" TEXT="mu&#xdf; mich einschr&#xe4;nken auf die Darstellung der Technik"/>
+<node CREATED="1786698610433" ID="ID_1146935453" MODIFIED="1786698618987" TEXT="Anpassungen / K&#xfc;rzungen">
+<node CREATED="1786698621077" ID="ID_1511769965" MODIFIED="1786698640928" TEXT="hatte zun&#xe4;chst eine ausf&#xfc;hrliche Motivation"/>
+<node CREATED="1786698641415" ID="ID_257654983" MODIFIED="1786698667311" TEXT="die Darstellung folgte den Design-Prinzipien"/>
+<node CREATED="1786698668027" ID="ID_1171670350" MODIFIED="1786698715996" TEXT="Anpassung: diese Hintergrund-Ebene entfernen"/>
+<node CREATED="1786698716740" ID="ID_1317224140" MODIFIED="1786698726842" TEXT="die Ankerpunkte aus den Slides entfernen">
+<node CREATED="1786698729755" ID="ID_1222373094" MODIFIED="1786698801068" TEXT="das AI-Thema und die Guidelines streichen">
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      das war ohnehin nur ein Extra, und letzlich off-topic
+    </p>
+  </body>
+</html>
+</richcontent>
+</node>
+<node CREATED="1786698804805" ID="ID_1022168735" MODIFIED="1786698816384" TEXT="die Verbindungen zu Berkely vs. MIT"/>
+<node CREATED="1786698824538" ID="ID_2983412" MODIFIED="1786698830260" TEXT="Seitengedanken und Jokes"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1754750859506" ID="ID_551478124" MODIFIED="1779389203874" TEXT="Animationen aufbauen">
-<icon BUILTIN="flag-yellow"/>
 </node>
 </node>
 <node BACKGROUND_COLOR="#ccb59b" COLOR="#6e2a38" CREATED="1755730987056" ID="ID_734596433" MODIFIED="1779389056508" TEXT="Fazit">

FrOSCon26/examples/egl-display.hpp

@@ -183,9 +183,10 @@ EglDisplay<PIX,WIDTH,HEIGHT>::openDisplay (Gtk::Window& appWindow)
 
   // use lib-GLEW to manage OpenGL extensions (notably GL Shader Language)
   GLenum glewErr = glewInit();
-  if (GLEW_OK != glewErr)
+////////////////////////////////////////////////////////////////////////////////////TODO for some reason I get glewErr == 4 ("unknown error"), but it works non the less
-    __FAIL ("could not bind OpenGL extensions through lib-GLEW:\n"
+//if (GLEW_OK != glewErr)
-           +string{reinterpret_cast<const char*> (glewGetErrorString(glewErr))});
+//  __FAIL ("could not bind OpenGL extensions through lib-GLEW:\n"
+//         +string{reinterpret_cast<const char*> (glewGetErrorString(glewErr))});
 
 
   auto compileShader = [](GLenum kind, string code)