Disabled v8-compile-cache to fix intermittent V8 deserializer crashes

[cmraible-bot]

Problem

CI intermittently fails with a fatal V8 crash during Build TS packages:

# Fatal error in , line 0
# unreachable code
v8::internal::Deserializer<v8::internal::Isolate>::ReadSingleBytecodeData
...
v8::internal::CodeSerializer::Deserialize
v8::internal::Compiler::GetSharedFunctionInfoForScriptWithCachedData

Example failing run: https://github.com/TryGhost/Ghost/actions/runs/22564490904/job/65358043431

Root cause

The dependency chain ts-node → v8-compile-cache-lib is responsible. When ts-node loads the TypeScript compiler it calls v8-compile-cache-lib.install(), which caches compiled V8 bytecode to disk in /tmp.

With Nx running 4 parallel worker processes (the default), multiple workers call this simultaneously and race to read/write the same blob cache files. This corrupts the bytecode, causing the crash on deserialization.

This is a known Node.js issue: nodejs/node#51555

The Node.js core team confirmed: "Incorrect use of the v8 code cache can lead to corruption and crashes like this... This might be especially true if you have concurrent processes or threads which need careful synchronization."

Fix

Set DISABLE_V8_COMPILE_CACHE=1 globally in the CI workflow environment. This is the confirmed workaround from the Node.js issue thread.

Performance impact

None. The bytecode cache is written to /tmp and discarded at the end of each run — it never persists between CI jobs. Every run was already starting cold.

Test plan

• Verify CI passes without the intermittent V8 crash on a few runs

[coderabbitai]

Walkthrough

The pull request sets DISABLE_V8_COMPILE_CACHE=1 in the env section of the CI workflow (.github/workflows/ci.yml) and adds comments explaining this disables the v8-compile-cache to avoid intermittent V8 deserializer crashes when parallel Nx workers race on shared bytecode cache files (cache location: /tmp, references Node.js issue 51555). No workflow logic or control flow was changed. Lines changed: +6 / -0.

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly and clearly describes the main change: disabling v8-compile-cache to fix intermittent V8 deserializer crashes, which matches the core purpose of the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description check	✅ Passed	The pull request description is directly related to the changeset, explaining the problem, root cause, fix, and performance impact of disabling v8-compile-cache in CI.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.20%. Comparing base (e7505d9) to head (7798580).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #26652   +/-   ##
=======================================
  Coverage   73.20%   73.20%           
=======================================
  Files        1534     1534           
  Lines      121034   121034           
  Branches    14635    14635           
=======================================
+ Hits        88598    88599    +1     
  Misses      31405    31405           
+ Partials     1031     1030    -1     

Flag	Coverage Δ
admin-tests	54.32% <ø> (+<0.01%)	⬆️
e2e-tests	73.20% <ø> (+<0.01%)	⬆️

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[troyciesco]

lgtm, link to the node issue was extremely helpful.

question/suggestion: does this happen on just browser tests, like the one linked in the description, or any job? (I don't think I've ever run into this before). if it is just on browser tests it might be worth running that once here.

[cmraible]

does this happen on just browser tests, like the one linked in the description, or any job?

It could happen on any job that builds all the typescript packages - browser tests, acceptance tests, legacy tests, etc, so it's run successfully at least a couple times on this PR 😄