[Server] Uncaught Error: Typed property Mcp\Server\Session\Session::$data must not be accessed before initialization

[ineersa]

Describe the bug
Trying to setup Streamable HTTP server and testing things.
might be minor issue or non-existent, but getting it when cancelling tool call.
Also this might be connected to actual PHAR and sessions, haven't dig it yet.

To Reproduce
Steps to reproduce the behavior:

1. Run HTTP Streamable server
2. Cancel tool call while it's running

Expected behavior
No errors

Logs

PHP Fatal error:  Uncaught Error: Typed property Mcp\Server\Session\Session::$data must not be accessed before initialization in phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Session/Session.php:54
Stack trace:
#0 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Protocol.php(144): Mcp\Server\Session\Session->save()
#1 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Transport/BaseTransport.php(133): Mcp\Server\Protocol->processInput()
#2 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Transport/StreamableHttpTransport.php(112): Mcp\Server\Transport\BaseTransport->handleMessage()
#3 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Transport/StreamableHttpTransport.php(295): Mcp\Server\Transport\StreamableHttpTransport->handlePostRequest()
#4 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Transport/Http/MiddlewareRequestHandler.php(42): Mcp\Server\Transport\StreamableHttpTransport->handleRequest()
#5 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Transport/StreamableHttpTransport.php(101): Mcp\Server\Transport\Http\MiddlewareRequestHandler->handle()
#6 phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server.php(53): Mcp\Server\Transport\StreamableHttpTransport->listen()
#7 /tmp/mcp/browser-mcp/browser-mcp-e1da33004e005e4e88a9c08aba15280789c3df6e-http-worker.php(96): Mcp\Server->run()
#8 {main}
  thrown in phar:///home/ineersa/mcp/browser-mcp/browser-mcp.phar/vendor/mcp/sdk/src/Server/Session/Session.php on line 54

Additional context
Add any other context about the problem here.

[chr-hertel]

Hi @ineersa, thanks for reporting - should be fixed with #252 which is merged to main already - can you confirm?

[ineersa]

@chr-hertel Thanks, swapped to main now canceling tool calls doesn't trigger exception!
Closing!