[youknowriad]

Related issues

• Related to Windows e2e flakiness (Buildkite build 23034: sites.test.ts › preserves an existing MySQL wp-config.php, site-navigation.test.ts › opens site at homepage, sites.test.ts › duplicates a site)

How AI was used in this PR

Claude Code read the Windows e2e log, traced every failed attempt to the bundled-PHP migration, and wrote the fix and test. I reviewed the diagnosis and the change.

Proposed Changes

• On first launch, the Desktop app starts several CLI processes at once, and each runs the migration that copies the bundled PHP into ~/.studio/php-bin. On Windows, one copy can hit a locked file. Its error handler then deleted the whole PHP folder, including the files the other process had just copied, and the delete itself threw (ENOTEMPTY/EPERM), so that CLI command failed too.
• That left a PHP folder with php.exe but most of its extensions gone. The migration only checks whether the folder exists, so it never repaired it, and sites failed to start with "PDO Driver for SQLite is missing". Every failed attempt in the Windows e2e run above shows this sequence. Users on a fresh Windows install can hit the same thing.
• Each process now copies into its own staging folder and renames it into place, so the PHP folder only ever appears complete. A process that loses the race discards its own copy and leaves the installed folder alone.
• Not covered here: anyone whose PHP folder is already broken needs to delete it once. A similar, non-fatal EBUSY race on the bundled WordPress copy still shows up in the logs.

Testing Instructions

• npm test -- apps/cli/migrations/tests/06-install-bundled-default-php.test.ts. The new case fails on trunk, where the copy overwrites a folder another process already installed.
• Check that Windows e2e no longer shows ENOTEMPTY ... php-bin or "PDO Driver for SQLite is missing" from createSite.
• Optional, on Windows: delete ~/.studio/php-bin, launch Studio and create a site. It should start.

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

🤖 Generated with Claude Code

[wpmobilebot]

📊 Performance Test Results

Comparing 55b7230 vs trunk

app-size

Metric	trunk	55b7230	Diff	Change
App Size (Mac)	930.76 MB	930.76 MB	+0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	55b7230	Diff	Change
load	1169 ms	1154 ms	15 ms	⚪ 0.0%

site-startup

Metric	trunk	55b7230	Diff	Change
siteCreation	8563 ms	8579 ms	+16 ms	⚪ 0.0%
siteStartup	5916 ms	5892 ms	24 ms	⚪ 0.0%

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Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)