pkgsrc/mk/haskell

Packaging guide for Haskell packages

PKGNAME

Packages that only make sense to be implemented in Haskell should have a prefix hs- to avoid conflicts with non-Haskell packages. Libraries fall into this category. Packages that install both a library and executables also fall into this, if their libraries are the main body and their executables are supplemental. mk/haskell.mk prepends the prefix by default.

Packages that happen to be implemented in Haskell but could have been done otherwise should not have the prefix hs-. Applications fall into this category. Packages that install libraries too also fall into this, if their executables are the main body. You can remove the prefix by declaring this in your Makefile:

PKGNAME=	${DISTNAME}

Tools

Some packages have build-time dependencies on external tools, which are typically Haskell source preprocessors. At the time of this writing the following tools are available via the variable USE_TOOLS:

• pkg-config (which isn't specific to Haskell of course)
• alex
• cpphs
• happy

mk/haskell.mk generates dummy scripts for these tools by default, which unconditionally aborts the build with an error message. This is to prevent packages from silently depending on the tools.

buildlink3.mk

Packages with the prefix hs- should have buildlink3.mk like this:

BUILDLINK_TREE+=	hs-distributive

.if !defined(HS_DISTRIBUTIVE_BUILDLINK3_MK)
HS_DISTRIBUTIVE_BUILDLINK3_MK:=

BUILDLINK_API_DEPENDS.hs-distributive+=	hs-distributive>=0.6.2
BUILDLINK_ABI_DEPENDS.hs-distributive+=	hs-distributive>=0.6.2.1nb2
BUILDLINK_PKGSRCDIR.hs-distributive?=	../../math/hs-distributive

.include "../../devel/hs-base-orphans/buildlink3.mk"
.include "../../math/hs-semigroups/buildlink3.mk"
.include "../../devel/hs-tagged/buildlink3.mk"
.endif	# HS_DISTRIBUTIVE_BUILDLINK3_MK

BUILDLINK_TREE+=	-hs-distributive

This is a buildlink3.mk for a package math/hs-distributive version 0.6.2.1. The important part of this is that buildlink3.mk should have both BUILDLINK_API_DEPENDS.* and BUILDLINK_ABI_DEPENDS.*. The latter should be set to the exact version of the package because a Haskell package, once compiled, can provide absolutely zero ABI compatibility with any other versions of the same package.

BUILDLINK_API_DEPENDS.* should have up to three version components but not more. This is because every Haskell package is supposed to follow the versioning policy described here. That is, for a version A.B.C.D the first two components A.B describes a major API version, whose change indicates a breaking one. The third component C desibes a minor API version whose change indicates a non-breaking API change. The fourth component D describes a patch version which introduces no API changes. It therefore doesn't make sense to include D in our BUILDLINK_API_DEPENDS.*.