project crash upon upload in snapshot dir

[haraldschilly]

I'm not sure if the upload POST and the crash are actually related, but they're at least right next to each other. EDIT: it's uploading, easy to reproduce.

2024-05-02T13:17:20.900Z: cocalc:debug:project:handle-message-from-hub received a message {"event":"query","id":"90721163-fc14-499e-8786-1647f9854ca0","...":"..."}

2024-05-02T13:17:27.693Z: cocalc:http:project:upload upload POST 

2024-05-02T13:17:27.693Z: cocalc:http:project:upload upload POST  ensure target path exists...  /home/user/.snapshots/2024-05-02-122434

2024-05-02T13:17:27.694Z: cocalc:http:project:upload upload POST  parsing form data...

2024-05-02T13:17:27.697Z: cocalc:error:project:BUG (uncaughtException) 
BUG ****************************************************************************
 {"errno":-13,"code":"EACCES","syscall":"open","path":"/home/user/.snapshots/...ipynb"} uncaught
Exception Error: EACCES: permission denied, open '/home/user/.snapshots/...ipynb'

Error: EACCES: permission denied, open '/home/user/.snapshots/...ipynb'
2024-05-02T13:17:27.698Z: cocalc:debug:jupyter:pool killKernel pid= 227