update readme

[ZuseZ4]

No description provided.

[samestep]

Thanks for documenting this! Currently on my machine this fails with the following error message:

error: the `-Z unstable-options` flag must also be passed to enable the flag `check-cfg`
error: the `-Z unstable-options` flag must also be passed to enable the flag `check-cfg`
error: could not compile `samples` (lib test)
warning: build failed, waiting for other jobs to finish...
error: could not compile `samples` (lib)

[ZuseZ4]

Yes, but that error should go away and the examples should compile if you pass the flag. I am not sure if it will be still needed once I rebased and the error message in this case at least is correct, so I didn't add it to the docs.

[samestep]

@ZuseZ4 so I should clean my Enzyme build and try again with the latest main and it will work?

[ZuseZ4]

No, the rebase is still work in progress. And I am not 100% sure if it will directly be sufficient to remove this error, I'll decide afterwards if I can get rid of it, or if I need to add it to the docs. This is the WIP rebase PR: #162
For now I'd recommend to just set the flag, that will be less work. Also keep in mind that some of the docs changed recently, mainly https://enzyme.mit.edu/rust/Debugging.html#supported-rustflags

Edit: To be clear the latest flags as per docs are only supported if you pull and rebuild, but that alone won't remove the error you've seen above.