diff --git a/dev/TODO.txt b/dev/TODO.txt
index 68abe56d..6b55cada 100644
--- a/dev/TODO.txt
+++ b/dev/TODO.txt
@@ -1,3 +1,5 @@
+- mipmaps are darker than the orginal in both srgb and linear modes? see e.g. puzzlewindow.lobster
+
 - Default ignoring return values is a really bad default, wonder if it is too late to change?
   Ideally it would error on ignored return values unless the function explicitly marks a return
   value as ignorable.
diff --git a/dev/src/builtins.cpp b/dev/src/builtins.cpp
index 4ca38ba1..0247dc61 100644
--- a/dev/src/builtins.cpp
+++ b/dev/src/builtins.cpp
@@ -751,7 +751,7 @@ nfr("tan", "angle", "F}", "F}",
     [](StackPtr &sp, VM &) { VECTOROP(tan(f.fval() * RAD)); });
 
 nfr("sincos", "angle", "F", "F}:2",
-    "the normalized vector indicated by angle (in degrees), same as xy { cos(angle), sin(angle) }",
+    "the normalized vector indicated by angle (in degrees), same as float2 { cos(angle), sin(angle) }",
     [](StackPtr &sp, VM &) {
         auto a = Pop(sp).fval();
         PushVec(sp, double2(cos(a * RAD), sin(a * RAD)));
diff --git a/dev/src/lobster/vmdata.h b/dev/src/lobster/vmdata.h
index f9f8ad62..6b24eaed 100644
--- a/dev/src/lobster/vmdata.h
+++ b/dev/src/lobster/vmdata.h
@@ -378,7 +378,7 @@ struct ToFlexBufferContext {
 
     bool ignore_unsupported_types = false;
     bool cycle_detect = false;
-    set<LObject *> seen_objects;
+    map<LObject *, flexbuffers::Builder::Value> seen_objects;
 
     iint max_depth = 100;
     iint cur_depth = 0;
@@ -386,7 +386,8 @@ struct ToFlexBufferContext {
     string max_depth_hit;
     flexbuffers::Builder::Value max_depth_hit_value;
     string cycle_hit;
-    flexbuffers::Builder::Value cycle_hit_value;
+
+    PrintPrefs pp = PrintPrefs(2, 50, true, -1);
 
     ToFlexBufferContext(VM &vm, size_t initial_size, flexbuffers::BuilderFlag flags)
         : vm(vm), builder(initial_size, flags) {}
diff --git a/dev/src/vmdata.cpp b/dev/src/vmdata.cpp
index 5ca12b7f..0eef7457 100644
--- a/dev/src/vmdata.cpp
+++ b/dev/src/vmdata.cpp
@@ -614,16 +614,28 @@ void ElemToFlexBuffer(ToFlexBufferContext &fbc, const TypeInfo &ti,
 }
 
 void LObject::ToFlexBuffer(ToFlexBufferContext &fbc) {
+    // Terrible C++: we need 2 variables to track this, because we can't init inserted_it
+    // with end() because it may get invalidated by the insert, and trying to test
+    // against the default constructed iterator is UB.
+    bool inserted = false;
+    map<LObject *, flexbuffers::Builder::Value>::iterator inserted_it;
     if (fbc.cycle_detect) {
-        if (fbc.seen_objects.find(this) == fbc.seen_objects.end()) {
-            fbc.seen_objects.insert(this);
+        auto it = fbc.seen_objects.find(this);
+        if (it == fbc.seen_objects.end()) {
+            inserted = true;
+            inserted_it = fbc.seen_objects.insert({ this, flexbuffers::Builder::Value{} }).first;
         } else {
-            fbc.cycle_hit = TypeName(fbc.vm);
-            if (fbc.cycle_hit_value.type_ == flexbuffers::FBT_NULL) {
-                fbc.builder.String("(dup_ref)");
-                fbc.cycle_hit_value = fbc.builder.LastValue();
+            if (it->second.type_ == flexbuffers::FBT_NULL) {
+                // A true cycle, object referred to while not finished.
+                fbc.cycle_hit = TypeName(fbc.vm);
+                string sd;
+                append(sd, "(cycle_ref: ", (size_t)this, ": ");
+                ToString(fbc.vm, sd, fbc.pp);
+                append(sd, ")");
+                fbc.builder.String(sd);
             } else {
-                fbc.builder.ReuseValue(fbc.cycle_hit_value);
+                // Just a DAG ref, we just make the FlexBuffer a DAG as well!
+                fbc.builder.ReuseValue(it->second);
             }
             return;
         }
@@ -655,6 +667,9 @@ void LObject::ToFlexBuffer(ToFlexBufferContext &fbc) {
         ElemToFlexBuffer(fbc, eti, i, 1, Elems(), fname, stti.elemtypes[i].defval);
     }
     fbc.builder.EndMap(start);
+    if (inserted) {
+        inserted_it->second = fbc.builder.LastValue();
+    }
 }
 
 void LVector::ToFlexBuffer(ToFlexBufferContext &fbc) {