`parallel/test-snapshot-reproducible` fails when ASLR is enabled

Comece por test/parallel/test-snapshot-reproducible.js, especialmente pela asserção na linha 47. Reproduza com ./configure && make e com o Linux ASLR definido como 1 ou 2; em seguida, compare o snapshot gerado com o ASLR desabilitado. Considera-se concluído quando a falha for corrigida ou reduzida a uma causa documentada específica do V8 ou do ambiente, com um próximo passo claro.

Testing main on linux:

# sysctl -w kernel.randomize_va_space=2
$ ./configure && make && ./node test/parallel/test-snapshot-reproducible.js
node:internal/assert/utils:146
  throw error;
  ^

AssertionError [ERR_ASSERTION]: Expected values to be strictly deep-equal:
+ actual - expected
... Skipped lines

  [
    '#include <cstddef>',
    '#include "env.h"',
    '#include "node_snapshot_builder.h"',
    '#include "v8.h"',
...
    'namespace node {',
+   'static const char v8_snapshot_blob_data[] = {4,0,0,0,1,0,0,0,43,108,-20,-8,-43,-25,-94,-55,49,52,46,54,46,50,48,50,46,51,52,45,110,111,100,101,46,50,49,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  // 0',
-   'static const char v8_snapshot_blob_data[] = {4,0,0,0,1,0,0,0,-99,103,75,7,-43,-25,-94,-55,49,52,46,54,46,50,48,50,46,51,52,45,110,111,100,101,46,50,49,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,  // 0',
    '0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,16,10,23,0,64,8,25,0,72,114,29,0,8,107,30,0,-120,98,31,0,-40,88,32,0,-85,6,-34,-64,-96,9,23,0,-83,24,96,0,0,0,0,86,0,0,0,96,0,0,0,0,  // 1',
    '0,0,0,0,96,0,0,0,0,0,0,0,0,96,0,0,0,0,-53,1,0,0,96,0,0,0,0,-84,1,0,0,96,0,0,0,0,-64,2,0,0,96,0,0,0,0,0,0,0,0,96,0,0,0,0,-30,0,0,0,11,5,24,98,0,2,  // 2',
    '5,24,34,1,2,5,24,-30,1,2,5,24,-94,2,2,5,24,98,3,2,5,24,34,4,2,5,24,-30,4,2,5,24,-94,5,2,5,24,98,6,2,5,24,34,7,2,5,24,-30,7,2,5,24,-94,8,2,5,24,98,9,2,1,76,7,101,  // 3',
    '15,69,64,97,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,64,98,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,64,96,0,0,0,0,0,0,0,0,7,-123,2,64,96,0,0,0,  // 4',
    '0,8,0,0,0,-127,0,91,64,1,20,83,69,97,0,0,0,0,96,0,0,0,0,0,0,0,1,0,0,0,93,1,20,83,69,97,0,0,0,0,96,0,0,0,0,0,0,0,1,0,0,0,93,1,20,83,69,97,0,0,0,0,96,0,  // 5',
...
    '26,-87,22,26,-11,27,26,93,28,26,101,28,26,105,34,26,69,37,26,73,37,26,77,37,26,81,37,26,85,37,26,89,37,26,93,37,26,97,37,26,101,37,26,-87,43,26,-83,43,26,-71,43,1,20,86,98,0,0,0,0,3,0,0,0,0,  // 42996',
+   '0,0,0,1,0,0,0,0,0,0,0,14,0,0,0,64,91,31,0,6,-71,2,5,24,66,66,4,4,8,95,4,73,33,11,15,0,-3,15,0,8,6,0,0,-3,15,4,96,6,-86,-127,-107,44,127,0,0,24,0,0,0,0,0,0,0,47,  // 42997',
+   '0,0,0,0,0,0,0,0,-107,26,0,8,8,0,0,-107,26,4,64,8,-102,-74,95,5,0,0,0,16,0,0,0,0,0,0,0,0,-99,39,0,8,2,0,0,-99,39,4,-64,2,-102,-74,95,5,0,0,0,48,0,0,0,0,0,0,0,51,  // 42998',
+   '0,0,0,0,0,0,0,52,0,0,0,0,0,0,0,53,0,0,0,0,0,0,0,54,0,0,0,0,0,0,0,0,-67,49,0,8,7,0,0,-67,49,4,64,7,-102,-74,95,5,0,0,0,16,0,0,0,0,0,0,0,0,-123,56,0,8,  // 42999',
+   '9,0,0,-123,56,4,64,9,-101,-74,95,5,0,0,0,16,0,0,0,0,0,0,0,0,-59,79,-128,32,32,0,0,0,0,0,0,0,0,-59,79,-108,32,37,0,0,0,0,0,0,0,0,-59,79,-104,32,38,0,0,0,0,0,0,0,0,-59,  // 43000',
+   '79,-100,32,39,0,0,0,0,0,0,0,0,-91,108,0,8,3,0,0,-91,108,4,96,3,-86,-127,-107,44,127,0,0,24,0,0,0,0,0,0,0,43,0,0,0,0,0,0,0,0,-75,108,0,8,0,0,0,-75,108,4,96,0,-102,-74,95,5,  // 43001',
+   '0,0,0,24,0,0,0,0,0,0,0,45,0,0,0,0,0,0,0,0,-67,108,0,8,5,0,0,-67,108,4,64,5,114,5,54,-2,85,0,0,16,0,0,0,0,0,0,0,0,-51,108,0,8,1,0,0,-51,108,4,96,1,-102,-74,95,5,  // 43002',
-   '0,0,0,1,0,0,0,0,0,0,0,14,0,0,0,64,91,31,0,6,-71,2,5,24,66,66,4,4,8,95,4,73,33,11,15,0,-3,15,0,8,6,0,0,-3,15,4,96,6,-86,33,30,70,127,0,0,24,0,0,0,0,0,0,0,47,  // 42997',
-   '0,0,0,0,0,0,0,0,-107,26,0,8,8,0,0,-107,26,4,64,8,36,-106,100,5,0,0,0,16,0,0,0,0,0,0,0,0,-99,39,0,8,2,0,0,-99,39,4,-64,2,36,-106,100,5,0,0,0,48,0,0,0,0,0,0,0,51,  // 42998',
-   '0,0,0,0,0,0,0,52,0,0,0,0,0,0,0,53,0,0,0,0,0,0,0,54,0,0,0,0,0,0,0,0,-67,49,0,8,7,0,0,-67,49,4,64,7,36,-106,100,5,0,0,0,16,0,0,0,0,0,0,0,0,-123,56,0,8,  // 42999',
-   '9,0,0,-123,56,4,64,9,36,-106,100,5,0,0,0,16,0,0,0,0,0,0,0,0,-59,79,-128,32,32,0,0,0,0,0,0,0,0,-59,79,-108,32,37,0,0,0,0,0,0,0,0,-59,79,-104,32,38,0,0,0,0,0,0,0,0,-59,  // 43000',
-   '79,-100,32,39,0,0,0,0,0,0,0,0,-91,108,0,8,3,0,0,-91,108,4,96,3,-86,33,30,70,127,0,0,24,0,0,0,0,0,0,0,43,0,0,0,0,0,0,0,0,-75,108,0,8,0,0,0,-75,108,4,96,0,36,-106,100,5,  // 43001',
-   '0,0,0,24,0,0,0,0,0,0,0,45,0,0,0,0,0,0,0,0,-67,108,0,8,5,0,0,-67,108,4,64,5,-52,-33,6,76,86,0,0,16,0,0,0,0,0,0,0,0,-51,108,0,8,1,0,0,-51,108,4,96,1,36,-106,100,5,  // 43002',
    '0,0,0,24,0,0,0,0,0,0,0,57,0,0,0,0,0,0,0,11,10,10,10,10',
    '};',
    'static const int v8_snapshot_blob_size = 2752216;',
    'static const uint8_t vm_cache_data[] = {171,6,222,192,82,189,255,151,217,50,0,32,97,100,152,163,213,231,162,201,96,21,0,0,0,0,0,0,0,0,0,0,1,36,81,3,109,1,7,196,96,0,0,0,0,151,2,0,0,1,8,7,33,15,4,4,33,3,112,7,181,1,122,0,  // 0',
    '0,0,0,205,0,0,0,2,4,6,0,179,5,156,36,26,100,22,64,26,76,26,68,26,64,23,220,3,14,0,22,203,2,22,80,26,60,22,112,27,216,3,14,0,22,104,22,203,2,26,124,27,168,9,14,0,22,143,7,26,68,26,76,26,  // 1',

    at Object.<anonymous> (/node/test/parallel/test-snapshot-reproducible.js:47:8)
    at Module._compile (node:internal/modules/cjs/loader:1947:14)
    at Object..js (node:internal/modules/cjs/loader:2087:10)
    at Module.load (node:internal/modules/cjs/loader:1669:32)
    at Module._load (node:internal/modules/cjs/loader:1450:12)
    at wrapModuleLoad (node:internal/modules/cjs/loader:260:19)
    at Module.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:154:5)
    at node:internal/main/run_main_module:33:47 {
  generatedMessage: true,
  code: 'ERR_ASSERTION',
  actual: [ <skipped> ],
  expected: [ <skipped> ],
  operator: 'deepStrictEqual',
  diff: 'simple'
}

Node.js v27.0.0-pre

Reproducible locally with gcc 15.3.0 and 16.1.1.
The byteranges that differ are randomized so the exact bytes are different each time. Everything else seems to be consistent.
Completely disabling ASLR (setting kernel/randomize_va_space to 0) makes the test pass. Conservative ASLR (1) still breaks it.

Not exactly sure when this started (maybe some of v8 upgrades?) nor whether it can be fixed (maybe on v8 side?) nor what else causes this (test passes on CI so i assume there's additional factor to it).