Add a broader "traceback hiding" mechanism

[nicoddemus]

The current __tracebackhide__ mechanism to hide internal code details from traceback entries is too brittle; some small refactor might start to show internal code details to users.

I propose adding a new __tracebackhideall__ mechanism which when found and set to True will strip all frames below it. This way we can add to __tracebackhideall__ at the module level of a package and any traceback from it will be hidden.

[nicoddemus]

xref: pytest-dev/pluggy#80

[RonnyPfannschmidt]

duplicate of #283

[RonnyPfannschmidt]

also i'm against adding more hooks and magic values, lets talk about what is internal and not via a better configuration

for consumers of sqlalchemy for example sqlalchemy may be internal (and those tracebacks can be long)

same goes for other frameworks

[RonnyPfannschmidt]

also in addition - for stuff like pytest-html it may be awesome to know which traceback bit belongs to which framework

because it can just make those expandable

CC @davehunt

[nicoddemus]

@RonnyPfannschmidt thanks for pointing it out, I have forgotten about the discussion that took place in that other thread. Closing this as duplicate.