diff --git a/src/backup/todo.txt b/src/backup/todo.txt
index cc37ad6..f411efd 100644
--- a/src/backup/todo.txt
+++ b/src/backup/todo.txt
@@ -3,6 +3,7 @@
 
 Debug session:
 - Report errorf - use coroutine dialogs
+    - Replace in render layer also
 
 Use session 1:
 - OpenCommand in command window freezes the app
diff --git a/src/text_editor/commands.cpp b/src/text_editor/commands.cpp
index 2dcedca..ff6ec94 100644
--- a/src/text_editor/commands.cpp
+++ b/src/text_editor/commands.cpp
@@ -654,12 +654,11 @@ String CodeSkipPatterns[] = {".git/", ".obj", ".o", ".pdb", ".exe"};
 String Coro_OpenCodeDir;
 
 void Coro_OpenCode(mco_coro *co) {
-    BlockArena arena = {};
-    Array<String> dirs = {arena};
+    Array<String> dirs = {CoCurr->arena};
     Add(&dirs, Coro_OpenCodeDir);
     int i = 0;
     for (int diri = 0; diri < dirs.len; diri += 1) {
-        for (FileIter it = IterateFiles(arena, dirs[diri]); IsValid(it); Advance(&it)) {
+        for (FileIter it = IterateFiles(CoCurr->arena, dirs[diri]); IsValid(it); Advance(&it)) {
             bool match = false;
             for (int endings_i = 0; endings_i < Lengthof(CodeSkipPatterns); endings_i += 1) {
                 String ending = CodeSkipPatterns[endings_i];
@@ -680,7 +679,6 @@ void Coro_OpenCode(mco_coro *co) {
             CoYield(co);
         }
     }
-    Release(&arena);
 }
 
 void OpenCode(String dir) {
@@ -707,6 +705,7 @@ void AddHook(Array<CommandData> *arr, String name, String binding, Function *fun
     Add(arr, n);
 }
 
+// @todo: rename to temp buffer? but there is already a thing like that...
 String Coro_YesNoCancel(mco_coro *co, BSet main, String question) {
     JumpGarbageBuffer(&main);
     NextActiveWindowID = main.window->id;
@@ -766,8 +765,7 @@ void Coro_Close(mco_coro *co) {
         return;
     }
 
-    Scratch scratch;
-    String question = Format(scratch, "Do you want to save [%S] before closing?", main.buffer->name);
+    String question = Format(CoCurr->arena, "Do you want to save [%S] before closing?", main.buffer->name);
     String result = Coro_YesNoCancel(co, main, question);
     if (result == "Yes") {
         SaveBuffer(main.buffer);
@@ -786,10 +784,10 @@ void Command_Close() {
 // Considerations with coroutines:
 // 1. Does scratch memory leak across Yield boundary? Or interacts badly with Yield stuff in any way?
 // 2. Are pointers and globals correct over time? Or might they get deleted etc.
+// 3. Imagine a scenario where the coroutine gets deleted before completion, will the memory leak?
 String Coro_CloseAllEx(mco_coro *co) {
-    Scratch scratch;
     BSet main = GetBSet(LastActiveLayoutWindowID);
-    Array<BufferID> buffers = {scratch};
+    Array<BufferID> buffers = {CoCurr->arena};
     For (Buffers) Add(&buffers, it->id);
     ForItem (id, buffers) {
         Buffer *it = GetBuffer(id);
@@ -800,7 +798,7 @@ String Coro_CloseAllEx(mco_coro *co) {
             continue;
         }
 
-        String question = Format(scratch, "Do you want to save [%S] before closing?", it->name);
+        String question = Format(CoCurr->arena, "Do you want to save [%S] before closing?", it->name);
         String result = Coro_YesNoCancel(co, main, question);
         it = GetBuffer(id, NULL);
         if (it && result == "Yes") {
diff --git a/src/text_editor/coroutines.cpp b/src/text_editor/coroutines.cpp
index 34067e7..bff67d4 100644
--- a/src/text_editor/coroutines.cpp
+++ b/src/text_editor/coroutines.cpp
@@ -1,10 +1,17 @@
 typedef void CoroutineProc(mco_coro *co);
+CoData *CoCurr = NULL;
+
+void CoDestroy(CoData *n) {
+    mco_destroy(n->co);
+    Release(&n->arena);
+}
 
 void CoRemove(String name) {
     IterRemove(ActiveCoroutines) {
         IterRemovePrepare(ActiveCoroutines);
         if (it.name == name) {
             mco_destroy(it.co);
+            Release(&it.arena);
             remove_item = true;
         }
     }
@@ -15,15 +22,19 @@ CoData *CoAddEx(CoroutineProc *proc, String name) {
     CoRemove(name);
     mco_desc desc = mco_desc_init(proc, 0);
 
-    mco_coro  *coro = NULL;
-    mco_result ok   = mco_create(&coro, &desc);
+    mco_coro *coro = NULL;
+    mco_result ok = mco_create(&coro, &desc);
     if (ok != MCO_SUCCESS) {
         ReportWarningf("failed to create coroutine %d", ok);
         return NULL;
     }
 
-    mco_resume(coro);
     Add(&ActiveCoroutines, {coro, name});
+    CoData *prev_curr = CoCurr;
+    CoCurr = GetLast(ActiveCoroutines);
+    ok = mco_resume(coro);
+    Assert(ok == MCO_SUCCESS);
+    CoCurr = prev_curr;
     return GetLast(ActiveCoroutines);
 }
 
@@ -37,14 +48,15 @@ void CoUpdate(Event *event) {
 
             mco_state status = mco_status(it.co);
             if (status == MCO_DEAD) {
-                mco_destroy(it.co);
+                CoDestroy(&it);
                 remove_item = true;
             } else {
                 mco_push(it.co, &event, sizeof(Event *));
+                CoCurr = &it;
                 mco_result ok = mco_resume(it.co);
                 if (ok != MCO_SUCCESS) {
                     ReportWarningf("failed to resume coroutine %d", ok);
-                    mco_destroy(it.co);
+                    CoDestroy(&it);
                     remove_item = true;
                 }
             }
diff --git a/src/text_editor/globals.cpp b/src/text_editor/globals.cpp
index feb14ee..b2ba2d7 100644
--- a/src/text_editor/globals.cpp
+++ b/src/text_editor/globals.cpp
@@ -87,7 +87,7 @@ Array<Variable> Variables;
 Array<Process> ActiveProcesses = {};
 Array<String> ProcessEnviroment = {};
 
-struct CoData { mco_coro *co; String name; bool dont_wait_until_resolved; };
+struct CoData { mco_coro *co; String name; BlockArena arena; bool dont_wait_until_resolved; void *user_ctx; };
 Array<CoData> ActiveCoroutines;