The installation did not work

The installer stops at the first thing that goes wrong, says what it was on a line that starts with error:, and changes nothing after it. Exit status 3 means it refused the platform or the machine; 1 means a step failed. To see every step without doing any, run sh install.sh --dry-run.

Once Noust is installed, this lists what deployments need and the command that fixes each missing piece:

noust setup doctor

In the console, the same list is under Settings > About Noust > Installation check.

The platform is refused

error: Noust does not install on Debian GNU/Linux 11 (bullseye) (amd64).
Debian 11 (Bullseye): Python 3.9; Noust needs 3.10 or later.
The platforms it does install on are listed in docs/PLATFORMS.md.
To try anyway, run it again with --force and, for a package, --target <repository directory>.

The distribution, its release or the processor is not on the list; the second line says why. Install on a release that is, or try at your own risk with --force.

The machine is too small

warning: Memory is 384 MB, under the 512 MB Noust needs to run. Builds are what need it; a swap file helps (noust server swap create).
error: This machine is smaller than Noust can run on.
The sizes are in docs/requirements.md. Run it again with --force to try anyway.

The warnings above the error say which size is short: memory, processors or free disk. Below 1 GB of memory or 10 GB of free disk, the installer warns and asks; below 512 MB or 3 GB, it refuses. Requirements has the sizes, and what a build needs on top.

The repository key is not the expected one

error: The repository key does not have the expected fingerprint. Nothing was installed.

The key the package repository serves is not the one the installer pins. Stop there: it can be a rotated key or a wrong one. When the repository key is rotated says how to tell them apart.

There is no package for the release

error: There is no package for AlmaLinux 9.4 (Seafoam Ocelot).
Use --method pip, or name a repository directory with --target if you know one fits.

You asked for a package (--method package) on a release that has none. Leave the option out: on the RHEL family the installer uses pip by itself, in a virtual environment under /opt/noust, and links noust into /usr/local/bin.

It is not run as root

error: Noust installs system packages and writes to /etc: run this as root.

Run it as root, or with sudo sh install.sh.

noust: command not found

After the one-line installer, noust is in /usr/bin (a package) or /usr/local/bin (pip). If you installed with pip yourself, it is on the PATH of the user who ran pip, not necessarily root's.

Preparing the server failed

error: noust setup init did not finish.
Fix what it reports, then run: noust setup init -y

The lines above it are what failed, usually the package manager's own words (a mirror that does not answer, a lock held by an automatic update). Fix it and run noust setup init -y.

The console did not start

noust web install    # the console's Python packages
noust web enable     # run it as a service

The package for the new version is not there yet

The packages are built after a release, one repository per distribution, which takes 15 to 30 minutes. See An update says it is on the way.