Release 0.9

Highlights

• The minimum supported Bazel version is now v0.24.

  The version is available from nixpkgs unstable and via
  official releases.

• Initial Windows support

  A non-trivial subset of rules_haskell is now working on Windows.
  See the project tracker
  for finished and ongoing work.

• Improved OSX support

  Due to the mach-o header size limit, we took extra measures to
  make sure generated library paths are as short as possible, so
  linking haskell binaries works even for large dependency graphs.

• Better Bindist support

  The default start script sets up a
  bindist-based project by default.

  rules_nixpkgs is no longer a required dependency of
  rules_haskell (but can still be used as backend).

• Full Haskell–C–Haskell Sandwich

  A haskell_library can be now be used nearly anywhere a
  cc_library can.

  The old cc_haskell_import and haskell_cc_import wrapper rules
  are no longer necessary and have been deprecated.

• Greatly improved REPL support

  A new haskell_repl rule allows to load multiple source targets by
  source, or compiled, as needed. Example usage:

  haskell_repl(
    name = "my-repl",
    # Collect all transitive Haskell dependencies from these targets.
    deps = [
        "//package-a:target-1",
        "//package-b:target-2",
    ],
    # Load targets by source that match these patterns.
    include = [
        "//package-a/...",
        "//packaga-b/...",
        "//common/...",
    ],
    # Don't load targets by source that match these patterns.
    exclude = [
        "//package-a/vendored/...",
    ],
  )
  

• Support for GHC plugins

  Each haskell_* rule now has a plugins attribute. It takes a
  list of bazel targets, which should be haskell_librarys that
  implement the GHC plugin
  specification.

• Initial Code Coverage support

  Measure coverage of your Haskell code. See the “Checking Code
  Coverage”
  section in the manual.

Compatibility Notice

hazel was merged into
rules_haskell, but
we are not yet certain about the exact interface we want to expose.
hazel is therefore not included in this release, and we can’t
guarantee the original, unmerged version is compatible with this
release. If you depend on hazel, please use a recent master commit
of rules_haskell.

Changed

• haskell_register_ghc_bindists is no longer re-exported from
  //haskell/haskell.bzl.
  You must now load that macro from //haskell:nixpkgs.bzl.

• rules_nixpkgs is no longer a dependency of rules_haskell.

• haskell_import has been renamed to haskell_toolchain_library.
  This is a substantial breaking change. But adapting to it should be
  as simple as

  sed -i 's/^haskell_import/haskell_toolchain_library/' **/BUILD{,.bazel}
  sed -i 's/"haskell_import"/"haskell_toolchain_library"/' **/BUILD{,.bazel}
  

  See #843.

• haskell_toolchain’s tools attribute is now a list of labels.
  Earlier entries take precendence. To migrate, add [] around your
  argument.
  See #854.

• The default outputs of haskell_library are now the static and/or
  shared library files, not the package database config and cache
  files.

Added

• haskell_repl rule that constructs a ghci wrapper that loads
  multiple targets by source.
  See #736.
• plugins attribute to haskell_* rules to load GHC plugins.
  See #799.
• The HaskellInfo and HaskellLibraryInfo providers are now
  exported and thus accessible by downstream rules.
  See #844.
• Generate version macros for preprocessors (c2hs, hsc2hs).
  See #847.
• bindist_toolchain rule gets haddock_flags and repl_ghci_args
  attributes.
• @repl targets write json file with build information, usable by
  IDE tools.
  See #695.

Deprecated

• haskell_cc_import; use cc_library instead.
  See #831.
• cc_haskell_import; just use haskell_library like a cc_library.
  See #831.

Fixed

• Support protobuf roots in haskell_proto_library.
  See #722.
• Made GHC bindist relocatable on *nix.
  See #853.
• Various other fixes