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

[NullVoxPopuli]

Similar to: #20995

but maybe more representative of real-world usage (renderComponent called from a modifier, or external library, etc).

When the owner is passed to renderComponent, and renderComponent is called multiple times, we get this error:

Error occurred:

- While rendering:
  {ROOT}
    (unknown template-only component)

index.js:122 Uncaught (in promise) TypeError: Cannot read properties of null (reading 'syscall')
    at Object.evaluate (index.js:122:17)
    at LowLevelVM.evaluateSyscall (index.js:2900:20)
    at LowLevelVM.evaluateInner (index.js:2879:64)
    at LowLevelVM.evaluateOuter (index.js:2876:10)
    at VM.next (index.js:4194:45)
    at VM._execute (index.js:4184:21)
    at VM.execute (index.js:4164:26)
    at index.js:4221:76
    at debug.runInTrackingTransaction (index.js:42:19)
    at TemplateIteratorImpl.sync (index.js:4221:37)

[github-actions]

Estimated Asset Sizes

Diff

--- main/out.txt	2026-01-30 19:10:24.000000000 +0000
+++ pr/./pr-21730181846/out.txt	2026-02-05 22:03:40.000000000 +0000
@@ -1,37 +1,37 @@
 ╔═══════╤═══════════╤═══════════╗
 ║       │ Min       │ Gzip      ║
 ╟───────┼───────────┼───────────╢
-║ Total │ 352.26 KB │ 203.67 KB ║
+║ Total │ 352.26 KB │ 203.55 KB ║
 ╚═══════╧═══════════╧═══════════╝
 
 ╔══════════════════════╤═══════════╤═══════════╗
 ║ @ember/*             │ Min       │ Gzip      ║
 ╟──────────────────────┼───────────┼───────────╢
-║ Total                │ 313.87 KB │ 181.82 KB ║
+║ Total                │ 313.87 KB │ 181.79 KB ║
 ╟──────────────────────┼───────────┼───────────╢
-║ -internals           │ 36.68 KB  │ 26.02 KB  ║
-║ application          │ 13.24 KB  │ 8.03 KB   ║
+║ -internals           │ 36.68 KB  │ 25.99 KB  ║
+║ application          │ 13.24 KB  │ 7.99 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   │ 1.6 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   │ 860 B     ║
 ║ instrumentation      │ 2.43 KB   │ 1.78 KB   ║
-║ modifier             │ 1.22 KB   │ 1011 B    ║
+║ modifier             │ 1.22 KB   │ 987 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     │ 510 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     │ 517 B     ║
 ║ template-compilation │ 429 B     │ 366 B     ║
-║ template-compiler    │ 123.33 KB │ 59.68 KB  ║
-║ template-factory     │ 370 B     │ 351 B     ║
+║ template-compiler    │ 123.33 KB │ 59.61 KB  ║
+║ template-factory     │ 370 B     │ 385 B     ║
 ║ test                 │ 923 B     │ 627 B     ║
 ║ utils                │ 4.11 KB   │ 3.63 KB   ║
 ║ version              │ 55 B      │ 131 B     ║
@@ -40,19 +40,19 @@
 ╔═════════════════╤══════════╤══════════╗
 ║ @glimmer/*      │ Min      │ Gzip     ║
 ╟─────────────────┼──────────┼──────────╢
-║ Total           │ 38.38 KB │ 21.85 KB ║
+║ Total           │ 38.38 KB │ 21.75 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    ║
+║ node            │ 175 B    │ 268 B    ║
 ║ opcode-compiler │ 1.11 KB  │ 905 B    ║
 ║ owner           │ 159 B    │ 202 B    ║
-║ program         │ 252 B    │ 333 B    ║
+║ program         │ 252 B    │ 308 B    ║
 ║ reference       │ 548 B    │ 544 B    ║
-║ runtime         │ 10.32 KB │ 5.3 KB   ║
+║ runtime         │ 10.32 KB │ 5.21 KB  ║
 ║ tracking        │ 1.34 KB  │ 1.18 KB  ║
 ║ util            │ 1.94 KB  │ 1.6 KB   ║
 ║ validator       │ 15.53 KB │ 6.9 KB   ║

Details

This PR

main

╔═══════╤═══════════╤═══════════╗ ║ │ Min │ Gzip ║ ╟───────┼───────────┼───────────╢ ║ Total │ 352.26 KB │ 203.55 KB ║ ╚═══════╧═══════════╧═══════════╝ ╔══════════════════════╤═══════════╤═══════════╗ ║ @ember/* │ Min │ Gzip ║ ╟──────────────────────┼───────────┼───────────╢ ║ Total │ 313.87 KB │ 181.79 KB ║ ╟──────────────────────┼───────────┼───────────╢ ║ -internals │ 36.68 KB │ 25.99 KB ║ ║ application │ 13.24 KB │ 7.99 KB ║ ║ array │ 13.05 KB │ 7.54 KB ║ ║ canary-features │ 304 B │ 419 B ║ ║ component │ 2.05 KB │ 1.6 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 │ 860 B ║ ║ instrumentation │ 2.43 KB │ 1.78 KB ║ ║ modifier │ 1.22 KB │ 987 B ║ ║ object │ 35.98 KB │ 22.1 KB ║ ║ owner │ 159 B │ 178 B ║ ║ renderer │ 630 B │ 510 B ║ ║ routing │ 59.37 KB │ 33.93 KB ║ ║ runloop │ 2.36 KB │ 1.5 KB ║ ║ service │ 1 KB │ 858 B ║ ║ template │ 654 B │ 517 B ║ ║ template-compilation │ 429 B │ 366 B ║ ║ template-compiler │ 123.33 KB │ 59.61 KB ║ ║ template-factory │ 370 B │ 385 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 │ 21.75 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 │ 268 B ║ ║ opcode-compiler │ 1.11 KB │ 905 B ║ ║ owner │ 159 B │ 202 B ║ ║ program │ 252 B │ 308 B ║ ║ reference │ 548 B │ 544 B ║ ║ runtime │ 10.32 KB │ 5.21 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 ║ ╚═════════════════╧══════════╧══════════╝

[NullVoxPopuli]

Normally, I'd say we backport this, but I don't think we can pre-great merge