vrc-sdk3.5-linux.patch

--- Packages.orig/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/API/VRCTools.cs	2023-12-15 17:36:51.390368366 -0500
+++ Packages/com.vrchat.base/Editor/VRCSDK/Dependencies/VRChat/API/VRCTools.cs	2023-12-15 17:37:10.234606341 -0500
@@ -108,7 +108,12 @@
                 {
                     continue;
                 }
-                var groups = (IEnumerable)groupsList?.GetValue(servicePointGroups.GetValue(scheduler));
+                var servicePointGroup = servicePointGroups?.GetValue(scheduler);
+                if (servicePointGroup == null)
+                {
+                    continue;
+                }
+                var groups = (IEnumerable)groupsList?.GetValue(servicePointGroup);
 
                 // we're going to retry finding the active service point
                 if (groups == null)

Run this via patch -p0 < vrc-sdk3.5-linux.patch in your project directory to fix silly broken build issues on Linux.