Instead of timeout error - The MongoCursor object has not been correctly initialized by its constructor

I use php driver in a cli php script. I have a find() query that takes a long time to complete ( ~1000 ms).

I receive the error "The MongoCursor object has not been correctly initialized by its constructor".

When I increase socketTimeoutMS the error disappear,

 so instead of MongoCursorTimeoutException or MongoExecutionTimeoutException I got a general error.

Isn't that a problem? 

Yes, this looks like a problem. Can you please first update to the
latest driver version (1.5.8) and if the issue still persists, file a
bug report at https://jira.mongodb.org/browse/PHP ? Please include a
full reproducible case if you can - including data and a script.