--- qtwebengine-everywhere-src-6.5.2/src/3rdparty/gn/src/gn/ninja_action_target_writer.cc	2023-07-07 17:40:32.000000000 +0000
+++ qtwebengine-everywhere-src-6.5.2/src/3rdparty/gn/src/gn/ninja_action_target_writer.cc	2023-08-08 13:07:42.745576000 +0000
@@ -122,6 +122,14 @@
     // strictly necessary for regular one-shot actions, but it's easier to
     // just always define unique_name.
     std::string rspfile = custom_rule_name;
+
+    //quick workaround if filename length > 255 - ".rsp", just cut the dirs starting from the end
+    //please note ".$unique_name" is not used at the moment
+    int pos = 0;
+    std::string delimiter("_");
+    while (rspfile.length() > 251 && (pos = rspfile.find_last_of(delimiter)) != std::string::npos)
+        rspfile = rspfile.substr(0,pos);
+
     if (!target_->sources().empty())
       rspfile += ".$unique_name";
     rspfile += ".rsp";