6. Package Description Format Specification History
Package descriptions need to specify the version of the
specification they need to be interpreted in via the
cabal-version
declaration. The following list describes
changes that occurred in each version of the cabal specification
relative to the respective preceding published version.
Note
The sequence of specification version numbers is not
contiguous because it’s synchronised with the version of the
Cabal
library. As a consequence, only even versions are
considered proper published versions of the specification as odd
versions of the Cabal
library denote unreleased development
branches which have no stability guarantee.
6.1. cabal-version: 3.12
License fields use identifiers from SPDX License List version
3.23 2024-02-08
.
6.2. cabal-version: 3.8
Added field
code-generators
totest-suite
stanzas. This enumerates executabes (possibly brought into scope bybuild-tool-depends
) that are run after all other preprocessors. These executables are invoked with a target dir for output, a sequence of all source directories with source files of local lib components that the given test stanza depends on, and following a double dash, all options cabal would pass to ghc for a build. They are expected to output a newline-separated list of generated modules which have been written to the targetdir. This can be used for driving doctests and other discover-style tests generated from source code.Added fields
extra-libraries-static
andextra-lib-dirs-static
to allow Haskell libraries to remember linker flags needed for fully static linking of system libraries into executables. The existing fieldpkgconfig-depends
can used to append the relevant output ofpkg-config --libs --static
to these new fields automatically. Whenextra-libraries-static
is not given, it defaults toextra-libraries
. Whenextra-lib-dirs-static
is not given, it defaults toextra-lib-dirs
.Wildcard matching has been slightly expanded. Matches are now allowed of the form
foo/**/literalFile
. Prior, double-star wildcards required the trailing filename itself be a wildcard.Allow the omission of the type field in test-suite and benchmark stanzas when the type can be inferred by the presence of main-is or test-module.
License fields use identifiers from SPDX License List version
3.16 2022-02-06
6.3. cabal-version: 3.6
License fields use identifiers from SPDX License List version
3.10 2020-08-03
Add
hsc2hs-options
6.4. cabal-version: 3.4
License fields use identifiers from SPDX License List version
3.9 2020-05-15
Dependencies to sublibraries must be specified explicitly, even for current package. For example:
build-depends: mypackage:my-sublib
This way you can have a sublibrary with the same name as some external dependency.Remove
-any
and-none
syntax for version ranges Use>=0
and<0
respectively.default-language
is optional. The Default value is to use the compiler’s default language.mixins
field allow specifying a sublibrary.
6.5. cabal-version: 3.0
New
library:visibility
for exposing sublibraries.New
pkg:lib
andpkg:{lib1,lib2}
syntax inbuild-depends
for depending on public sublibraries from other packages.Added the
extra-dynamic-library-flavours
field to specify non-trivial variants of dynamic flavours. It isextra-library-flavours
but for shared libraries. Mainly useful for GHC’s RTS library.Free text fields (e.g.
description
) preserve empty lines and indentation. In other words, you don’t need to add dots for blank lines.License fields use identifiers from SPDX License List version
3.6 2019-07-10
Remove deprecated
hs-source-dir
,extensions
andbuild-tools
fields.Common stanzas are now allowed also in the beginning of conditional sections. In other words, the following is valid
library import deps if flag(foo) import foo-deps
Allow redundant leading or trailing commas in package fields with optional commas, such as
library:exposed-modules
Require fields with optional commas to consistently omit or place commas between elements.
Changed the behavior of
extra-bundled-libraries
field. The naming convention of dynamic library files (e.g. generated by a custom build script) has changed. For library names prefixed with “C”, the dynamic library file name(s) must be of the form lib<library-name>.<dyn-library-extension>* instead of the old libC<library-name>-ghc<ghc-flavour><ghc-version>.<dyn-library-extension>New set-notation syntax for
==
and^>=
operators, seebuild-depends
field documentation for examples.Allow more whitespace in
mixins
fieldWildcards are disallowed in
pkgconfig-depends
, Yet the pkgconfig format is relaxed to accept e.g. versions like1.1.0h
.New
autogen-includes
for specifyinginstall-includes
which are autogenerated (e.g. by aconfigure
script).New
asm-sources
andasm-options
fields added for supporting bundled foreign routines implemented in assembler.New
cmm-sources
andcmm-options
fields added for supporting bundled foreign primops implemented in C–.
6.6. cabal-version: 2.4
Wildcard matching has been expanded. All previous wildcard expressions are still valid; some will match strictly more files than before. Specifically:
Double-star (
**
) wildcards are now accepted for recursive matching immediately before the final slash; they must be followed by a filename wildcard (e.g.,foo/**/*.html
is valid;foo/**/bar/*.html
andfoo/**/**/*.html
,foo/**/bar.html
are all invalid). As**
was an error in globs before, this does not affect any existing.cabal
files that previously worked. (Caveat: Double-star wildcards indata-files
directories, e.g.data-files: data/**/*.csv
, are only supported correctly from Cabal 3.0.)Wildcards now match when the pattern’s extensions form a suffix of the candidate file’s extension, rather than requiring strict equality (e.g., previously
*.html
did not matchfoo.en.html
, but now it does).
License fields use identifiers from SPDX License List version
3.2 2018-07-10
6.7. cabal-version: 2.2
New
library:virtual-modules
field added.New
cxx-sources
andcxx-options
fields added for supporting bundled foreign routines implemented in C++.New
extra-bundled-libraries
field for specifying additional custom library objects to be installed.Extended
if
control structure with support forelif
keyword.Changed default rules of
build-type
field to infer “build-type:” for “Simple”/”Custom” automatically.license
field syntax changed to require SPDX expression syntax (using SPDX license list version3.0 2017-12-28
).Allow redundant leading or trailing commas in package fields (which require commas) such as
build-depends
.
6.8. cabal-version: 2.0
New
library:signatures
andmixins
fields added for supporting How to use Backpack modules.New
build-tool-depends
field added for adding build-time dependencies of executable components.New
custom-setup:autogen-modules
field added for declaring modules which are generated at build time.Support for new PVP caret-style version operator (
^>=
) added tobuild-depends
.Add support for new
foreign-library
stanza.Add support for sublibrary stanzas.
New CPP Macro
CURRENT_PACKAGE_VERSION
.
6.9. cabal-version: 1.24
New
custom-setup
stanza andcustom-setup:setup-depends
field added for specifying dependencies of customSetup.hs
scripts.CPP Macros
VERSION_$pkgname
andMIN_VERSION_$pkgname
are now also generated for the current package.New CPP Macros
CURRENT_COMPONENT_ID
andCURRENT_PACKAGE_KEY
.New
extra-framework-dirs
field added for specifying extra locations to find OS X frameworks.
6.10. cabal-version: 1.22
New
library:reexported-modules
field.Support for
-none
version constraint added tobuild-depends
.New
license
typeISC
added.
6.11. cabal-version: 1.20
Add support for new
license-files
field for declaring multiple license documents.New CPP Macro
MIN_TOOL_VERSION_$buildtool
.New
license
typesBSD2
andMPL-2.0
added.
6.12. cabal-version: 1.18
Add support for new
extra-doc-files
field for specifying extra file assets referenced by the Haddock documentation.New
license
typeAGPL
andAGPL-3
added.Add support for specifying a C/C++/obj-C source file in
executable:main-is
field.Add
getSysconfDir
operation toPaths_
API.
6.13. cabal-version: 1.16
Todo
this needs to be researched; there were only few changes between 1.12 and 1.18;
6.14. cabal-version: 1.12
Change syntax of
cabal-version
to support the new recommendedcabal-version: x.y
style