Retired names

nano-ros’s cmake variables use one prefix, NROS_. Older releases used NANO_ROS_ for some of them, and the release before this one still accepted those spellings as deprecated aliases. They are now retired: a configure that sets one — in a CMakeLists.txt, with -D on the command line, or left behind in a build directory’s CMakeCache.txt — stops with an error that names the replacement. Nothing is adopted under the new name any more, so rename the old spelling where you set it.

Retired	Use instead
`NANO_ROS_PLATFORM`	`NROS_PLATFORM`
`NANO_ROS_FEATURES`	`NROS_FEATURES`
`NANO_ROS_SAFETY_E2E`	`NROS_SAFETY_E2E`
`NANO_ROS_ROS_EDITION`	`NROS_ROS_EDITION`
`NANO_ROS_GEN_CACHE_DIR`	`NROS_GEN_CACHE_DIR`
`NANO_ROS_SKIP_BOOTSTRAP`	`NROS_SKIP_BOOTSTRAP`
`NANO_ROS_BUILD_CODEGEN`	`NROS_BUILD_CODEGEN`
`NANO_ROS_CMAKE_DIR`	`NROS_CMAKE_DIR`
`NANO_ROS_RMW`	`NROS_RMW`
`NANO_ROS_BOARD`	`NROS_BOARD`
`NANO_ROS_ROOT` (cmake variable)	`NROS_REPO_DIR`
`NANO_ROS_ROOT <path>` (keyword of `nano_ros_workspace()` and friends)	`NROS_REPO_DIR <path>`

Retired board names

The host board is linux. Two other words used to name it and are now refused wherever a board is named — nros setup <board>, nros new --platform, nros new --image … --board, an [image.<id>] board row — with an error that names linux. One more word named the bare-metal MPS2-AN385 board by its emulator, and another the RISC-V ThreadX board; both are refused the same way, naming the board’s one name:

Retired	Use instead	Why
`native`	`linux`	`native` names every general-purpose host, and the host board builds on Linux only
`posix`	`linux`	`posix` is the platform (`nros-platform-posix`), not a board
`qemu-mps2-an385`	`mps2-an385-baremetal`	names the emulator, not the board: QEMU is how the AN385 image is run
`threadx-qemu-riscv64`	`rv-virt-threadx`	names the emulator, not the board: QEMU is how the RISC-V `virt` image is run

posix stays correct as a PLATFORM name and in [tasks.*.posix]. This page is the only place in the book that spells any of these words as a board.

Retired knob spellings

Build-time knobs have one env spelling, NROS_<ID>, held in the knob registry packages/tooling/nros-zephyr-build/knobs.toml. The older spellings below were read with a deprecation warning for one release. They are now retired: a build that finds one set — exported in the environment, in a cargo [env] table, or as an [image.<id>] env row in system.toml — stops with an error that names the replacement. Nothing is read under the old name any more, so rename it where you set it.

Retired	Use instead
`ZPICO_BATCH_MULTICAST_SIZE`	`NROS_ZENOH_BATCH_MULTICAST_SIZE`
`ZPICO_BATCH_UNICAST_SIZE`	`NROS_ZENOH_BATCH_UNICAST_SIZE`
`ZPICO_FRAG_MAX_SIZE`	`NROS_ZENOH_FRAG_MAX_SIZE`
`ZPICO_GET_POLL_INTERVAL_MS`	`NROS_ZENOH_GET_POLL_INTERVAL_MS`
`ZPICO_GET_REPLY_BUF_SIZE`	`NROS_ZENOH_GET_REPLY_BUF_SIZE`
`ZPICO_GRAPH_CACHE_SIZE`	`NROS_ZENOH_GRAPH_CACHE_SIZE`
`ZPICO_GRAPH_DISCOVERY`	`NROS_ZENOH_GRAPH_DISCOVERY`
`ZPICO_MAX_LARGE_SUBSCRIBERS`	`NROS_ZENOH_MAX_LARGE_SUBSCRIBERS`
`ZPICO_MAX_LIVELINESS`	`NROS_ZENOH_MAX_LIVELINESS`
`ZPICO_MAX_PENDING_GETS`	`NROS_ZENOH_MAX_PENDING_GETS`
`ZPICO_MAX_PUBLISHERS`	`NROS_ZENOH_MAX_PUBLISHERS`
`ZPICO_MAX_QUERYABLES`	`NROS_ZENOH_MAX_QUERYABLES`
`ZPICO_MAX_SESSIONS`	`NROS_ZENOH_MAX_SESSIONS`
`ZPICO_MAX_SUBSCRIBERS`	`NROS_ZENOH_MAX_SUBSCRIBERS`
`ZPICO_MAX_TL_PUBLISHERS`	`NROS_ZENOH_MAX_TL_PUBLISHERS`
`ZPICO_PUBLISHER_TX_BUFFER_SIZE`	`NROS_ZENOH_PUBLISHER_TX_BUFFER_SIZE`
`ZPICO_READ_TASK_PRIORITY`	`NROS_ZENOH_READ_PRIORITY`
`ZPICO_SERVICE_BUFFER_SIZE`	`NROS_ZENOH_SERVICE_BUFFER_SIZE`
`ZPICO_SMOLTCP_BUFFER_SIZE`	`NROS_SMOLTCP_BUFFER_SIZE`
`ZPICO_SMOLTCP_CONNECT_TIMEOUT_MS`	`NROS_SMOLTCP_CONNECT_TIMEOUT_MS`
`ZPICO_SMOLTCP_MAX_SOCKETS`	`NROS_SMOLTCP_MAX_SOCKETS`
`ZPICO_SMOLTCP_MAX_UDP_SOCKETS`	`NROS_SMOLTCP_MAX_UDP_SOCKETS`
`ZPICO_SMOLTCP_SOCKET_TIMEOUT_MS`	`NROS_SMOLTCP_SOCKET_TIMEOUT_MS`
`ZPICO_SUBSCRIBER_LARGE_SIZE`	`NROS_ZENOH_SUBSCRIBER_LARGE_SIZE`
`ZPICO_SUBSCRIBER_RING_DEPTH`	`NROS_ZENOH_SUBSCRIBER_RING_DEPTH`
`ZPICO_SUBSCRIBER_SIZE_THRESHOLD`	`NROS_ZENOH_SUBSCRIBER_SIZE_THRESHOLD`
`ZPICO_TL_RETAIN_BYTES`	`NROS_ZENOH_TL_RETAIN_BYTES`
`ZPICO_TL_RETAIN_DEPTH`	`NROS_ZENOH_TL_RETAIN_DEPTH`
`ZPICO_TX_BATCH`	`NROS_ZENOH_TX_BATCH`
`ZPICO_TX_BATCH_FLUSH_MS`	`NROS_ZENOH_TX_BATCH_FLUSH_MS`
`ZPICO_TX_SPLIT_LOCK`	`NROS_ZENOH_TX_SPLIT_LOCK`

The same ZPICO_* words remain the zenoh-pico shim’s own C macro names (a -DZPICO_MAX_QUERYABLES=… the build passes to the C compiler). Those are generated from the knob, never set by hand, and are not on this list.

Retired knobs

Some knobs are gone, not renamed: what they configured no longer exists. Every spelling of one is refused with an error that says why and what to set instead.

zenoh-pico 1.10 runs the lease and keep-alive on its executor thread, which is the read task, so the separate lease task and its settings are retired:

Retired	Where it was set	What to do
`NROS_ZENOH_LEASE_PRIORITY`, `ZPICO_LEASE_TASK_PRIORITY`	environment, cargo `[env]`, `[image.<id>] env`	remove it; `NROS_ZENOH_READ_PRIORITY` prioritises the thread that now runs the lease
`[image.<id>.knobs.zenoh] lease_priority`	`system.toml`	remove it; use `read_priority`
`CONFIG_NROS_ZENOH_LEASE_PRIORITY`	`prj.conf` / Kconfig fragments	remove it; Kconfig reports it as an undefined symbol. Use `CONFIG_NROS_ZENOH_READ_PRIORITY`
`zenoh_lease_priority`, `zenoh_lease_stack_bytes`	`[node.rt]` / `[node.rt.freertos]`	remove them; `zenoh_read_priority` / `zenoh_read_stack_bytes` configure that task
`.keepalive_priority`, `.keepalive_stack_bytes`	`nros_app_config_t.scheduling`	remove them; the C compiler rejects an initializer that names either
`ZPICO_LEASE_TASK_PRIORITY` (C define)	`-D` to the zenoh shim	remove it; the shim `#error`s on it

zpico_set_task_config takes two arguments now, the executor task’s priority and stack size.

A board descriptor’s knobs are a top-level [knobs.<group>] table. The per-board [board.knobs.<group>] spelling is retired the same way: a descriptor that still states it fails to load, naming [knobs].

Retired runtime aliases and macro forms

Deprecated in release 0.5.0-nros2, retired after it. Each is now an ERROR naming its replacement — never silently ignored, because an ignored locator dials the default router and reads as “no delivery”.

Retired	Use instead	What happens now
`ZENOH_LOCATOR` (env)	`NROS_LOCATOR`	startup error (Rust panic / `InitError::RetiredEnvVar`; C/C++ init returns invalid-argument and logs it)
`ZENOH_MODE` (env)	`NROS_SESSION_MODE`	same
`nros::main!(board = X)`	`nros::main!()` + `[image.<id>] board` in `system.toml`; an out-of-tree board crate states `[package.metadata.nros.board] type = "::my_board::MyBoard"`	`compile_error!`
`--features rmw-xrce` on the PX4 companions	nothing — the xrce backend is unconditional	the feature no longer exists (cargo: unknown feature)

Retired commands

Retired	Use instead	What happens now
`nros new entry <name> --platform zephyr`	`nros materialize <bringup>:<image>`, which writes the image’s generated entry into your workspace as a package you own under `src/`; or, for an application that owns its west build, A Zephyr App You Build with West	the book no longer teaches it: a workspace generates the entry for each image, so there is nothing to scaffold by hand

A build directory from an older release

An older nano-ros wrote some of these names into the cache itself, so a build directory it first configured carries them even though nothing sets them now. The error lists those entries and prints the command that drops exactly them:

cmake -U NANO_ROS_PLATFORM -U NANO_ROS_RMW <build-dir>

Deleting the build directory’s CMakeCache.txt works too.

What is not on this list

nano_ros_DIR and nano_ros_ROOT are CMake’s own find_package(nano_ros) hints and keep their spelling.

NANO_ROS_ROOT as an environment variable is retired by its own rule: a configure that finds it set stops, naming NROS_REPO_DIR.

The error table stays: a retired name is refused for good, naming what to type. Dropping the rows would turn -DNANO_ROS_PLATFORM=zephyr (or a stale cache entry an older nano-ros wrote) into an unknown variable, and the configure would build the default platform without a word.

Design background

RFC-0093: board naming states reach — why a board is not named for its emulator
RFC-0103: one owner per fact — the one NROS_<ID> knob spelling
RFC-0110: zenoh-pico executor driving — why the lease task is gone

Keyboard shortcuts

nano-ros Book