Write the fake adb from a child process so no test's fork holds it open

[LucaCappelletti94]

The Android proof tool's adb retry tests failed now and then with "Text file busy". Each test writes a stand-in adb script and runs it at once. Another test thread could fork while the script was still open for writing, and the child kept that descriptor until its own exec, so running the script failed. Measured on main, 16 of 60 runs of the proof tool's tests failed this way.

The helper now has a child sh write the script, so no descriptor open for writing it ever exists in the test process. 200 runs in a row passed afterwards.

Parallel Android proof tests could fail with “Text file busy” when a fork inherited an open descriptor for the fake adb script. The test helper now delegates script creation and executable permissions to a child shell process, so the test process does not hold the script open for writing.

The change addresses the reported intermittent failure. The author reports that 200 consecutive runs passed after the fix.

[coderabbitai]

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ℹ️ Recent review info

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• Run ID: 50faa12c-eaba-4661-9fd8-aad8c6fa86f7

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📥 Commits

Reviewing files that changed from the base of the PR and between f84efe8 and c23091c.

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📒 Files selected for processing (1)

• crates/connetto-test-harness/src/bin/connetto-android-proof.rs

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📝 Walkthrough

Walkthrough

The fake_adb helper now creates its mock executable through a child shell process. It streams the script to the child and asserts that the child completes successfully.

Changes

Mock ADB script creation

Layer / File(s)	Summary
Child shell script creation crates/connetto-test-harness/src/bin/connetto-android-proof.rs	fake_adb streams the script to a spawned shell, which writes the executable and applies executable permissions. The helper asserts that the child starts and exits successfully.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Bug fix

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Merge Risk: ⚪ Minimal · up to c2309

The helper writes the fake adb script in a child process and closes its input before waiting for completion. No actionable merge-blocking risk is established.

🚥 Pre-merge checks | ✅ 11 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Title check		The title accurately describes the change and uses the imperative, but it is 71 characters and exceeds the 70-character limit.	Shorten the title to 70 characters or fewer, for example: "Write fake adb from a child process"

✅ Passed checks (11 passed)

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage		Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
No Placeholder Implementations		No added line introduces a prohibited placeholder or deferral marker. The diff adds the child-process writer and related comments, and the added-line scan found no TODO, FIXME, HACK, XXX, unimplemente…
No Blanket Diagnostic Suppression		The pull request adds no blanket diagnostic suppression. The added lines only import Write, build the script, spawn sh, write through stdin, and assert process success. No Rust allow/deny attr…
Behavior Change Carries A Test		The only changed file is crates/connetto-test-harness/src/bin/connetto-android-proof.rs. The changed code is inside the existing #[cfg(test)] mod tests and updates the fake_adb test helper. This…
Git Dependency Pin Stays Out Of Commits		Cargo.lock is unchanged in the reviewed range. The failure condition requires the pull request to add or modify Cargo.lock, so the manifest git dependencies do not trigger this check.
Crate Readme Is The Crate Documentation		The check is inapplicable. The pull request changes only crates/connetto-test-harness/src/bin/connetto-android-proof.rs; it does not change README.md, and the repository root has no src/lib.rs.
Pre-Alpha Has No Deployments		The workspace version is 0.0.0, so the check applies. The added lines only implement child-process writing for the fake adb script. They mention none of the prohibited deployment or migration topics.
Prose Punctuation		The added prose contains no semicolons, dash punctuation, curly quotes, or ellipsis glyphs. Semicolons in the added shell script are code, which the check permits.

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.40%. Comparing base (f84efe8) to head (c23091c).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #145   +/-   ##
=======================================
  Coverage   86.40%   86.40%           
=======================================
  Files         163      163           
  Lines       39726    39726           
  Branches    39726    39726           
=======================================
+ Hits        34325    34326    +1     
+ Misses       3525     3524    -1     
  Partials     1876     1876           

Flag	Coverage Δ
client	55.58% <ø> (+0.01%)	⬆️
rest	51.66% <ø> (-0.36%)	⬇️
server	55.20% <ø> (-0.01%)	⬇️

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