Crash in `sst dev` when running on Windows (possibly Cursor related)

[fdmarc]

When I run sst dev on Windows, and edit my project in Cursor, after several minutes, the sst dev process crashes with the following output:

✖  Building...

Error: EPERM: operation not permitted, watch 'C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\.sst.config.1771583712297.mjs'

Trace: Error: EPERM: operation not permitted, watch 'C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\.sst.config.1771583712297.mjs'
    at FSWatcher.<computed> (node:internal/fs/watchers:254:19)
    at Object.watch (node:fs:2539:36)
    at createFsWatchInstance (C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\node_modules\.pnpm\chokidar@3.6.0\node_modules\chokidar\lib\nodefs-handler.js:119:15)
    at setFsWatchListener (C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\node_modules\.pnpm\chokidar@3.6.0\node_modules\chokidar\lib\nodefs-handler.js:166:15)
    at NodeFsHandler._watchWithNodeFs (C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\node_modules\.pnpm\chokidar@3.6.0\node_modules\chokidar\lib\nodefs-handler.js:331:14)
    at NodeFsHandler._handleFile (C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\node_modules\.pnpm\chokidar@3.6.0\node_modules\chokidar\lib\nodefs-handler.js:395:23)
    at NodeFsHandler._addToNodeFs (C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\node_modules\.pnpm\chokidar@3.6.0\node_modules\chokidar\lib\nodefs-handler.js:637:21)
    at process.<anonymous> (file:///C:/Users/User/dev/github.com/flipdishbytes/clients-onboarding/node_modules/.pnpm/sst@2.48.5_@jest+transform@29.7.0_@jest+types@3_7c72cfecc85688706a1aa3cb8c62b7dc/node_modules/sst/cli/sst.js:58:21)
    at process.emit (node:events:508:28)
    at process.processEmit [as emit] (C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\node_modules\.pnpm\signal-exit@3.0.7\node_modules\signal-exit\index.js:199:34)
    at process._fatalException (node:internal/process/execution:159:25)
    at throwUnhandledRejectionsMode (node:internal/process/promises:394:5)
    at processPromiseRejections (node:internal/process/promises:475:17)
    at process.processTicksAndRejections (node:internal/process/task_queues:106:32)
 ELIFECYCLE  Command failed with exit code 1.

This setup has worked for me for years, but this problem has started happening in the last few months only.

I'm running the following software:

Windows 11 (Pro 25H2 26200.7840).
SST: v2.48.5
CDK: v2.179.0
Constructs: v10.3.0
Node v24.10.0
pnpm 10.12.4 (we use pnpm not npm)
fnm 1.38.1 (for managing Node)
GNU bash, version 5.2.37(1)-release (x86_64-pc-msys)
Cursor Version: 2.5.17 (user setup)
Windows Terminal Version: 1.23.20211.0

The error is EPERM: operation not permitted, watch 'C:\Users\User\dev\github.com\flipdishbytes\clients-onboarding\.sst.config.1771583712297.mjs'

I'm not sure what could be causing this. I'm opening the issue here incase anyone else has similar problems. As I debug I will comment below.