fix: ensure tab-groups data dir exists before acquiring lock file#11
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grigoryosifov wants to merge 1 commit into
Open
fix: ensure tab-groups data dir exists before acquiring lock file#11grigoryosifov wants to merge 1 commit into
grigoryosifov wants to merge 1 commit into
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When a user invokes any stateful browser_tab_group / browser_tabs call before
~/.ultimate-playwright-mcp/ has been created (fresh machine or wiped data dir),
acquireLock() calls writeFileSync(LOCK_PATH, ..., { flag: 'wx' }) which fails
with ENOENT because the parent directory is missing. The outer catch then tries
readFileSync(LOCK_PATH, ...) which also fails with ENOENT, the loop retries,
and depending on host filesystem behavior either takes until maxWaitMs to give
up or appears to hang indefinitely. From a user's perspective: the first tool
call freezes.
Fix: call ensureDir() at the top of acquireLock(), same as readRegistry() and
writeRegistry() already do.
Credit to @moltenrooster (Joe Lemay) for identifying the root cause while
setting up ultimate-playwright-mcp on a machine with no prior data dir.
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Problem
When a user invokes any stateful
browser_tab_group/browser_tabscall before~/.ultimate-playwright-mcp/has been created (fresh machine or wiped data dir),acquireLock()calls:```ts
writeFileSync(LOCK_PATH, String(process.pid), { flag: "wx" });
```
which fails with
ENOENTbecause the parent directory is missing. The outer catch then triesreadFileSync(LOCK_PATH, ...)which also fails withENOENT, the loop retries, and depending on host filesystem behavior either takes untilmaxWaitMsto give up or — in practice on some macOS setups — appears to hang indefinitely under load. From a user's perspective: the first stateful tool call freezes.Reproducer
rm -rf ~/.ultimate-playwright-mcp/browser_tab_groupaction=list(or any action that hits the registry)Fix
Call
ensureDir()at the top ofacquireLock(), exactly asreadRegistry()andwriteRegistry()already do. One-line addition.Tested
~/.ultimate-playwright-mcp/on a test macOS machine (Chrome 147, macOS 26.2 ARM64)browser_tab_group action=listhung;browser_tabs action=listhung similarly