The Cabal library and related infrastructure is still under active development. New features are being added and limitations and bugs are being fixed. This requires internal changes and often user visible changes as well. We therefor cannot promise complete future-proof stability, at least not without halting all development work.
This section documents the aspects of the Cabal interface that we can promise to keep stable and which bits are subject to change.
This is backwards compatible and mostly forwards compatible. New fields can be added without breaking older versions of Cabal. Fields can be deprecated without breaking older packages.
./setup configure
--prefix
--user
--ghc, --hugs
--verbose
--prefix
./setup build
./setup install
./setup register
./setup copy
The Cabal library follows the Package Versioning Policy. This means that within a stable major release, for example 1.2.x, there will be no incompatible API changes. But minor versions increments, for example 1.2.3, indicate compatible API additions.
The Package Versioning Policy does not require any API guarantees between major releases, for example between 1.2.x and 1.4.x. In practise of course not everything changes between major releases. Some parts of the API are more prone to change than others. The rest of this section gives some informal advice on what level of API stability you can expect between major releases.
defaultMain
defaultMainWithHooks defaultUserHooks
But regular defaultMainWithHooks isn't stable since UserHooks changes.
UserHooks The hooks API will change in the future
Distribution.* is mostly declarative information about packages and is somewhat stable.
The index format is a partly stable interface. It consists of a tar.gz file that contains directories with .cabal files in. In future it may contain more kinds of files so do not assume every file is a .cabal file. Incompatible revisions to the format would involve bumping the name of the index file, i.e., 00-index.tar.gz, 01-index.tar.gz etc.