Horizon.Config.Error

The declared platform, and cabal's reason it is not one.

The declared platform, and the architecture cabal does not know.

The declared platform, and the operating system cabal does not know.

The declared index state, and the time the generator ran: until then the set would change as Hackage grows.

The declared index state, the local index read at it (as a config names it, and its file), the newest entry it holds, if any, and when it was last updated: a copy whose newest entry is no later than the state, last updated before it, may lack what was published until then, so the set would depend on when the machine last updated it.

The declared index state, the index a solve fetched just now, and the newest entry it holds, if any: the index itself ends there.

The declared index state, if any, the index to read, and the directory holding no copy of it.

An index, its file, and why it cannot be read.

doCheck True with includeTests False: the suites would run without their dependencies.

doBenchmark True with includeBenchmarks False.

A package, a patch declared for it, and what is wrong with it.

A local package, its directory, and what is wrong with it.

Packages declared flags, patches or native libraries that the set does not contain.

The bases a config names with on, more than one: a set is built on exactly one.

A package pinned with hackageFrom from a repository not declared before it.

A declared repository, its threshold, and how many root keys it lists: the threshold must be at least one and at most that many.

Packages given module, suite or backend facts that are not local packages of this repository.

What the horizon.vx declares about the local packages that their .cabal files say otherwise.

The packages whose pkgs/*.nix could not be rendered, each with the reason. The lock leaves them out, so the next run retries them.

A line of a horizon.vx read back, and why it is not a statement.

A flake.lock, and why no toolchain could be read from it.

Absolute, or reaching outside the repository the flake's source carries.

A character a bare Nix path literal cannot spell.

A local package's source is this repository, so it is edited, not patched.

Declared more than once for the same package.

Absolute, or reaching outside the repository the flake's source carries.

A character a bare Nix path literal cannot spell.

cabal2nix reads a package from the one .cabal in its directory.

The .cabal's file name, which a bare Nix path literal cannot spell.

The .cabal, and cabal's reason it is not a package description.

The .cabal, and the package it describes instead.

Why the directory or its .cabal could not be read.