onmcu update

Run an on-demand update check with:

onmcu update

The command compares the installed version with the latest published release. If a newer version is available, it prints both the release-notes link and the platform-specific installer command. It does not replace the executable automatically, contact the OnMCU controller, or require an API key.

When the versions match, the command reports that the CLI is up to date. A source build or prerelease newer than the published release is reported as being ahead.

Automatic update notices

Other onmcu commands check for a newer stable release in the background and may finish with a notice like this:

A new version of onmcu is available: 0.2.0 -> 0.3.0
Release notes: https://github.com/onmcu/onmcu-rs/releases/latest
Update with:
  <platform-specific installer command>

The background lookup:

• runs only when standard error is connected to a terminal;
• caches a successful lookup for 24 hours;
• is skipped when CI or ONMCU_NO_UPDATE_CHECK is enabled;
• ignores prereleases and network failures; and
• waits no more than one second at the end of a command.

While a cached version is newer than the installed CLI, later interactive commands may repeat the notice without making another network request.

Set ONMCU_NO_UPDATE_CHECK=1 to disable automatic checks:

export ONMCU_NO_UPDATE_CHECK=1

An explicit onmcu update always performs a fresh lookup, even when automatic checks are disabled or CI is set. If that lookup fails, the command returns exit code 15.

Update cache

A stable release result is cached for 24 hours. A failed background lookup or prerelease result is retried after one hour. The cache is stored at $XDG_CACHE_HOME/onmcu/update-check.json, normally ~/.cache/onmcu/update-check.json on Linux and macOS, and below %LOCALAPPDATA% on Windows.

The cache contains only the lookup time and published version. It can be deleted safely.