I got the following error when trying the same thing. I have no idea why, since the ioctl_write_ptr and ioctl_read macros are still supposed to be around. I can't spot any relevant change in nix that would cause this to happen. Help would be appreciated.
The relavent change is.
All Cargo features have been removed from the default set. Users will need to specify which features they depend on in their Cargo.toml.
I've bumped the dependency, added the feature, run the autopkgtest and uploaded the package.
