Fix; renderComponent error: 'attempted to close a tracking frame, but one was not open' by NullVoxPopuli · Pull Request #20995 · emberjs/ember.js

NullVoxPopuli · 2025-10-30T14:37:59Z

This happens when:

renderComponent is called twice, sequentially
the renderedComponent calls another component
and the rendered component calls a helper
the owner is passed to renderComponent

these 4 things are required to reproduce the error

not passing the owner results in a passing test
not invoking a child component results in a passing test
not invoking a helper results in a passing test

github-actions · 2025-10-30T14:39:20Z

Estimated Asset Sizes

Diff

--- main/out.txt	2026-01-30 19:10:24.000000000 +0000
+++ pr/./pr-21730794287/out.txt	2026-02-05 22:24:50.000000000 +0000
@@ -1,34 +1,34 @@
 ╔═══════╤═══════════╤═══════════╗
 ║       │ Min       │ Gzip      ║
 ╟───────┼───────────┼───────────╢
-║ Total │ 352.26 KB │ 203.67 KB ║
+║ Total │ 352.26 KB │ 203.58 KB ║
 ╚═══════╧═══════════╧═══════════╝
 
 ╔══════════════════════╤═══════════╤═══════════╗
 ║ @ember/*             │ Min       │ Gzip      ║
 ╟──────────────────────┼───────────┼───────────╢
-║ Total                │ 313.87 KB │ 181.82 KB ║
+║ Total                │ 313.87 KB │ 181.74 KB ║
 ╟──────────────────────┼───────────┼───────────╢
-║ -internals           │ 36.68 KB  │ 26.02 KB  ║
-║ application          │ 13.24 KB  │ 8.03 KB   ║
+║ -internals           │ 36.68 KB  │ 26.01 KB  ║
+║ application          │ 13.24 KB  │ 7.94 KB   ║
 ║ array                │ 13.05 KB  │ 7.54 KB   ║
 ║ canary-features      │ 304 B     │ 419 B     ║
-║ component            │ 2.05 KB   │ 1.56 KB   ║
+║ component            │ 2.05 KB   │ 1.58 KB   ║
 ║ controller           │ 1.96 KB   │ 1.45 KB   ║
 ║ debug                │ 11.73 KB  │ 8.14 KB   ║
 ║ deprecated-features  │ 31 B      │ 77 B      ║
 ║ destroyable          │ 561 B     │ 383 B     ║
 ║ enumerable           │ 259 B     │ 387 B     ║
-║ helper               │ 1.08 KB   │ 805 B     ║
+║ helper               │ 1.08 KB   │ 799 B     ║
 ║ instrumentation      │ 2.43 KB   │ 1.78 KB   ║
-║ modifier             │ 1.22 KB   │ 1011 B    ║
+║ modifier             │ 1.22 KB   │ 979 B     ║
 ║ object               │ 35.98 KB  │ 22.1 KB   ║
 ║ owner                │ 159 B     │ 178 B     ║
-║ renderer             │ 630 B     │ 508 B     ║
-║ routing              │ 59.37 KB  │ 33.92 KB  ║
+║ renderer             │ 630 B     │ 513 B     ║
+║ routing              │ 59.37 KB  │ 33.93 KB  ║
 ║ runloop              │ 2.36 KB   │ 1.5 KB    ║
 ║ service              │ 1 KB      │ 858 B     ║
-║ template             │ 654 B     │ 523 B     ║
+║ template             │ 654 B     │ 537 B     ║
 ║ template-compilation │ 429 B     │ 366 B     ║
 ║ template-compiler    │ 123.33 KB │ 59.68 KB  ║
 ║ template-factory     │ 370 B     │ 351 B     ║

Details

This PR main

╔═══════╤═══════════╤═══════════╗
║       │ Min       │ Gzip      ║
╟───────┼───────────┼───────────╢
║ Total │ 352.26 KB │ 203.58 KB ║
╚═══════╧═══════════╧═══════════╝

╔══════════════════════╤═══════════╤═══════════╗
║ @ember/*             │ Min       │ Gzip      ║
╟──────────────────────┼───────────┼───────────╢
║ Total                │ 313.87 KB │ 181.74 KB ║
╟──────────────────────┼───────────┼───────────╢
║ -internals           │ 36.68 KB  │ 26.01 KB  ║
║ application          │ 13.24 KB  │ 7.94 KB   ║
║ array                │ 13.05 KB  │ 7.54 KB   ║
║ canary-features      │ 304 B     │ 419 B     ║
║ component            │ 2.05 KB   │ 1.58 KB   ║
║ controller           │ 1.96 KB   │ 1.45 KB   ║
║ debug                │ 11.73 KB  │ 8.14 KB   ║
║ deprecated-features  │ 31 B      │ 77 B      ║
║ destroyable          │ 561 B     │ 383 B     ║
║ enumerable           │ 259 B     │ 387 B     ║
║ helper               │ 1.08 KB   │ 799 B     ║
║ instrumentation      │ 2.43 KB   │ 1.78 KB   ║
║ modifier             │ 1.22 KB   │ 979 B     ║
║ object               │ 35.98 KB  │ 22.1 KB   ║
║ owner                │ 159 B     │ 178 B     ║
║ renderer             │ 630 B     │ 513 B     ║
║ routing              │ 59.37 KB  │ 33.93 KB  ║
║ runloop              │ 2.36 KB   │ 1.5 KB    ║
║ service              │ 1 KB      │ 858 B     ║
║ template             │ 654 B     │ 537 B     ║
║ template-compilation │ 429 B     │ 366 B     ║
║ template-compiler    │ 123.33 KB │ 59.68 KB  ║
║ template-factory     │ 370 B     │ 351 B     ║
║ test                 │ 923 B     │ 627 B     ║
║ utils                │ 4.11 KB   │ 3.63 KB   ║
║ version              │ 55 B      │ 131 B     ║
╚══════════════════════╧═══════════╧═══════════╝

╔═════════════════╤══════════╤══════════╗
║ @glimmer/*      │ Min      │ Gzip     ║
╟─────────────────┼──────────┼──────────╢
║ Total           │ 38.38 KB │ 21.85 KB ║
╟─────────────────┼──────────┼──────────╢
║ destroyable     │ 2.78 KB  │ 1.38 KB  ║
║ encoder         │ 81 B     │ 171 B    ║
║ env             │ 38 B     │ 87 B     ║
║ global-context  │ 886 B    │ 545 B    ║
║ manager         │ 977 B    │ 627 B    ║
║ node            │ 175 B    │ 244 B    ║
║ opcode-compiler │ 1.11 KB  │ 905 B    ║
║ owner           │ 159 B    │ 202 B    ║
║ program         │ 252 B    │ 333 B    ║
║ reference       │ 548 B    │ 544 B    ║
║ runtime         │ 10.32 KB │ 5.3 KB   ║
║ tracking        │ 1.34 KB  │ 1.18 KB  ║
║ util            │ 1.94 KB  │ 1.6 KB   ║
║ validator       │ 15.53 KB │ 6.9 KB   ║
║ vm              │ 495 B    │ 569 B    ║
║ wire-format     │ 1.84 KB  │ 1.35 KB  ║
╚═════════════════╧══════════╧══════════╝

╔═══════╤═══════════╤═══════════╗
║       │ Min       │ Gzip      ║
╟───────┼───────────┼───────────╢
║ Total │ 352.26 KB │ 203.67 KB ║
╚═══════╧═══════════╧═══════════╝

╔══════════════════════╤═══════════╤═══════════╗
║ @ember/*             │ Min       │ Gzip      ║
╟──────────────────────┼───────────┼───────────╢
║ Total                │ 313.87 KB │ 181.82 KB ║
╟──────────────────────┼───────────┼───────────╢
║ -internals           │ 36.68 KB  │ 26.02 KB  ║
║ application          │ 13.24 KB  │ 8.03 KB   ║
║ array                │ 13.05 KB  │ 7.54 KB   ║
║ canary-features      │ 304 B     │ 419 B     ║
║ component            │ 2.05 KB   │ 1.56 KB   ║
║ controller           │ 1.96 KB   │ 1.45 KB   ║
║ debug                │ 11.73 KB  │ 8.14 KB   ║
║ deprecated-features  │ 31 B      │ 77 B      ║
║ destroyable          │ 561 B     │ 383 B     ║
║ enumerable           │ 259 B     │ 387 B     ║
║ helper               │ 1.08 KB   │ 805 B     ║
║ instrumentation      │ 2.43 KB   │ 1.78 KB   ║
║ modifier             │ 1.22 KB   │ 1011 B    ║
║ object               │ 35.98 KB  │ 22.1 KB   ║
║ owner                │ 159 B     │ 178 B     ║
║ renderer             │ 630 B     │ 508 B     ║
║ routing              │ 59.37 KB  │ 33.92 KB  ║
║ runloop              │ 2.36 KB   │ 1.5 KB    ║
║ service              │ 1 KB      │ 858 B     ║
║ template             │ 654 B     │ 523 B     ║
║ template-compilation │ 429 B     │ 366 B     ║
║ template-compiler    │ 123.33 KB │ 59.68 KB  ║
║ template-factory     │ 370 B     │ 351 B     ║
║ test                 │ 923 B     │ 627 B     ║
║ utils                │ 4.11 KB   │ 3.63 KB   ║
║ version              │ 55 B      │ 131 B     ║
╚══════════════════════╧═══════════╧═══════════╝

╔═════════════════╤══════════╤══════════╗
║ @glimmer/*      │ Min      │ Gzip     ║
╟─────────────────┼──────────┼──────────╢
║ Total           │ 38.38 KB │ 21.85 KB ║
╟─────────────────┼──────────┼──────────╢
║ destroyable     │ 2.78 KB  │ 1.38 KB  ║
║ encoder         │ 81 B     │ 171 B    ║
║ env             │ 38 B     │ 87 B     ║
║ global-context  │ 886 B    │ 545 B    ║
║ manager         │ 977 B    │ 627 B    ║
║ node            │ 175 B    │ 244 B    ║
║ opcode-compiler │ 1.11 KB  │ 905 B    ║
║ owner           │ 159 B    │ 202 B    ║
║ program         │ 252 B    │ 333 B    ║
║ reference       │ 548 B    │ 544 B    ║
║ runtime         │ 10.32 KB │ 5.3 KB   ║
║ tracking        │ 1.34 KB  │ 1.18 KB  ║
║ util            │ 1.94 KB  │ 1.6 KB   ║
║ validator       │ 15.53 KB │ 6.9 KB   ║
║ vm              │ 495 B    │ 569 B    ║
║ wire-format     │ 1.84 KB  │ 1.35 KB  ║
╚═════════════════╧══════════╧══════════╝

…, but one was not open'

void-mAlex · 2026-02-05T22:52:15Z

packages/@ember/-internals/glimmer/tests/integration/components/render-component-test.ts

+          `<div id="a"></div><br>`,
+          `<div id="b"></div>`,
+          `{{render A 'a' owner}}`,
+          `{{render B 'b' owner}}`,


Suggested change

`{{render B 'b' owner}}`,

`{{render B 'b' owner}}`,

`{{render B 'b'}}`,

`{{render A 'a'}}`,

what happens when you mix owner and non owner calls?

NullVoxPopuli mentioned this pull request Oct 30, 2025

Fix; renderComponent error: 'Cannot read property of undefined: reading syscall' #20996

Open

NullVoxPopuli force-pushed the nvp/renderComponent/syscall-error branch from 06aba0f to 8693073 Compare November 19, 2025 18:00

NullVoxPopuli mentioned this pull request Nov 21, 2025

Advance RFC #1099 "renderComponent" to Stage Recommended emberjs/rfcs#1151

Draft

17 tasks

NullVoxPopuli added 3 commits February 5, 2026 17:12

Reproduce renderComponent error: 'attempted to close a tracking frame…

c6ae8fa

…, but one was not open'

Update assertion

dced266

Error happens in a strict-only environment as well

2cf4b1c

NullVoxPopuli force-pushed the nvp/renderComponent/syscall-error branch from 8693073 to 2cf4b1c Compare February 5, 2026 22:12

NullVoxPopuli added 2 commits February 5, 2026 17:18

Fix

6a659f8

Lint

bb06fee

NullVoxPopuli marked this pull request as ready for review February 5, 2026 22:28

NullVoxPopuli changed the title ~~Reproduce renderComponent error: 'attempted to close a tracking frame, but one was not open'~~ Fix; renderComponent error: 'attempted to close a tracking frame, but one was not open' Feb 5, 2026

void-mAlex reviewed Feb 5, 2026

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Fix; renderComponent error: 'attempted to close a tracking frame, but one was not open'#20995

Fix; renderComponent error: 'attempted to close a tracking frame, but one was not open'#20995
NullVoxPopuli wants to merge 5 commits intoemberjs:mainfrom
NullVoxPopuli:nvp/renderComponent/syscall-error

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