A fingerprint written into a recipe names one particular copy of the base — the
copy on whichever machine the person typing it was using. On any other mesh that
copy has never existed, so the build stops on its first line with a message
about an image nobody can look up. Three modules in the catalogue were in
exactly that state, and the line each of them replaced was equally dead.
A module now names the module and artifact instead, and the mesh answers with
what it holds. The builder is still a thing that clones, builds and answers: the
answer travels with the question, because only the mesh knows what it has.
A base the mesh has not built is refused before anything is built, naming which
module has to exist first.
This is how a mesh is raised: the installer carries this program and runs it
once, before anything exists, to produce the control plane from the same
repository and path every later rebuild will use. What raises the mesh is then
the same thing that maintains it, rather than a second mechanism exercised once
per new mesh — which is how often enough to rot.
With nowhere to publish, an image stays in the machine's own runtime and is
named by the digest of its own configuration: the same identity the installer
has always used for the image it carried.