Change:
This flag will set which lints should be set to the [forbid level](lints/levels.html#forbid). <ins> ## `-Z`: set unstable options This flag will allow you to set unstable options of rustc. In order to set multiple options, the -Z flag can be used multiple times. For example: `rustc -Z verbose -Z time`. Specifying options with -Z is only available on nightly. To view all available options run: `rustc -Z help`. </ins> ## `--cap-lints`: set the most restrictive lint level This flag lets you 'cap' lints, for more, [see here](lints/levels.html#capping-lints).

Discussion:
Right now, The Unstable Book is just a list of unstable lang/lib features. There are other things like compiler flags which are also considered unstable that should be documented in The Unstable Book. This requires adjusting a bit to accommodate other sections. Right now I'm thinking that all sections (features, flags, etc) will live in their own subdirectory.
Relevant thread:
Reminder for future self: remove this hack
This may not be the issue, but there are a number of stable features that are actually just "stable", like target specs and llvm plugins, where we don't even try to maintain stability. It would be nice to have a discussion of those somewhere.
I'm waiting on to merge before I work on this.
Copying text from
This was partially completed in
In suggests that we should keep the library features minimal; I agree. They should exist, so you can see everything that's unstable, but there's no reason to duplicate their docs.
regarding unsafe command line options, one can see them via . it looks like the options are all defined . they seem to all be exposed on . seems like we should be able to autogenerate all the unsafe command line options pages like we do for the other unstable book sections (via )
Triage: we now have , but it doesn't talk about .
I just saw that the Unstable Book already contains a list of unstable compiler flags which I guess means that this issue is already solved right? Maybe we should create a separate issue for the missing -Z description in and close this one? Maybe also create a separate issue to autogenerate the unsafe nightly commands for the Unstable Book. That way we can keep the tasks that need to be done clearly isolated. If you agree I can create these new issues with a nice description of what needs to be done!
Yes! Alternatively, if this is something you'd like to send a PR for, we can just keep this issue open and use that PR to close it. I would prefer not to, I don't think this is the job for the unstable book.
I'll go ahead and do that then! I can understand that you have this view!

I do not really have much of a view myself on this, though I do think that we should keep duplication between the docs and other docs to a minimum (or to keep documentation duplication to a minimum in general because its easier to maintain). The docs are probably a better place to document this. However, this does lead me to the following question: Currently, there is already a in the unstable book. For example the flag. I think we should either try to complete this section or remove/move it to the docs all-together. What is your opinion on this?
Moving it to the docs seems appropriate to me!
I created an issue for this here: Then we can use this issue for adding -Z to the compiler flags section!