From a551143367ab204a989794b7e956b1826a646213 Mon Sep 17 00:00:00 2001
From: Judah Jacobson <judah@users.noreply.github.com>
Date: Sun, 20 May 2018 11:05:43 -0700
Subject: [PATCH] Fix #185: Support and use autogen-modules.

This makes it possible to generate tarballs without generated modules
(which would be regenerated anyway when the package is build).
See tensorflow/haskell#180 for an example of the issues that causes.

Unfortunately, this required us stopping using `hpack` in our packages
that generate proto files.  `hpack`, when you use the `autogen-modules`
field,
`cabal-version: >= 2.0` when the file

I mitigated the situation a little by changing the Cabal test script to
only try to `sdist` packages that we're planning to release.
---
 .travis.yml                                   |  2 +-
 docs/releasing.md                             | 22 +----
 proto-lens-combinators/package.yaml           | 50 ------------
 .../proto-lens-combinators.cabal              | 65 +++++++++++++++
 proto-lens-discrimination/package.yaml        | 56 -------------
 .../proto-lens-discrimination.cabal           | 81 +++++++++++++++++++
 proto-lens-protobuf-types/package.yaml        | 44 ----------
 .../proto-lens-protobuf-types.cabal           | 61 ++++++++++++++
 proto-lens-protoc/src/Data/ProtoLens/Setup.hs |  5 ++
 proto-lens-tests-dep/package.yaml             | 34 --------
 .../proto-lens-tests-dep.cabal                | 39 +++++++++
 release.sh                                    | 21 -----
 travis-cabal.sh                               | 65 ++++++++++-----
 13 files changed, 298 insertions(+), 247 deletions(-)
 delete mode 100644 proto-lens-combinators/package.yaml
 create mode 100644 proto-lens-combinators/proto-lens-combinators.cabal
 delete mode 100644 proto-lens-discrimination/package.yaml
 create mode 100644 proto-lens-discrimination/proto-lens-discrimination.cabal
 delete mode 100644 proto-lens-protobuf-types/package.yaml
 create mode 100644 proto-lens-protobuf-types/proto-lens-protobuf-types.cabal
 delete mode 100644 proto-lens-tests-dep/package.yaml
 create mode 100644 proto-lens-tests-dep/proto-lens-tests-dep.cabal
 delete mode 100755 release.sh

diff --git a/.travis.yml b/.travis.yml
index a4c92349..83c9ecf2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,7 +36,7 @@ before_install:
       cabal)
         export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$HOME/.local/bin:$HOME/.cabal/bin:$PATH;;
     esac
-  - curl -L https://github.com/commercialhaskell/stack/releases/download/v1.6.1/stack-1.6.1-linux-x86_64.tar.gz | tar xz --wildcards --strip-components=1 -C $HOME/.local/bin '*/stack'
+  - curl -L https://github.com/commercialhaskell/stack/releases/download/v1.7.1/stack-1.7.1-linux-x86_64.tar.gz | tar xz --wildcards --strip-components=1 -C $HOME/.local/bin '*/stack'
   - curl -L https://github.com/google/protobuf/releases/download/v3.0.0-beta-2/protoc-3.0.0-beta-2-linux-x86_64.zip > protoc-release.zip
   - unzip -p protoc-release.zip protoc > $HOME/.local/bin/protoc
   - chmod a+x $HOME/.local/bin/protoc
diff --git a/docs/releasing.md b/docs/releasing.md
index a2ebe9e1..af0cf7a1 100644
--- a/docs/releasing.md
+++ b/docs/releasing.md
@@ -17,26 +17,8 @@ since they are intended only for use within this repository:
 - Make sure you are on a commit that has been merged upstream to `google/proto-lens`.
 
 ## Steps
-1. For each package *without* autogenerated proto modules, simply run (from the root of the repo):
+First, run `stack build` at the top level.  Then, for each package that you want to upload, run
 
         stack upload {name-of-package}
 
-  Then verify that they've been uploaded successfully by visiting `hackage.org` in a web browser.
-
-2. For packages *with* autogenerated proto-modules (currently:
-`proto-lens-protobuf-types` and `proto-lens-combinators`): these are a little
-harder to upload due to #185.  We have a script for running `sdist`:
-
-        ./release.sh
-
-  Then, for each package that should be uploaded:
-
-        cabal upload {package}/dist/{path}.tar.gz
-
-3. Finally, tag each uploaded package with its version and push it back to upstream.  For example:
-
-        git tag -a proto-lens-v0.3.0.0 -m "Release proto-lens v0.3.0.0"
-        ...
-        git remote add upstream git@github.com:google/proto-lens.git
-        git push upstream --follow-tags  # See: https://stackoverflow.com/a/26438076
-    
+Then verify that they've been uploaded successfully by visiting `hackage.org` in a web browser.
diff --git a/proto-lens-combinators/package.yaml b/proto-lens-combinators/package.yaml
deleted file mode 100644
index caecf3a8..00000000
--- a/proto-lens-combinators/package.yaml
+++ /dev/null
@@ -1,50 +0,0 @@
-name: proto-lens-combinators
-version: '0.1.0.10'
-synopsis: Utilities functions to proto-lens.
-description: Useful things for working with protos.
-category: Data
-author: Zie Weaver
-maintainer: zearen+protolens@google.com
-copyright: Google Inc.
-license: BSD3
-github: google/proto-lens/proto-lens-combinators
-extra-source-files:
-  - tests/combinators.proto
-  - Changelog.md
-
-custom-setup:
-  dependencies:
-    - base >= 4.8 && < 4.12
-    - Cabal
-    - proto-lens-protoc == 0.3.*
-
-dependencies:
-  - base >= 4.8 && < 4.12
-  - proto-lens-protoc == 0.3.*
-  - lens-family == 1.2.*
-
-library:
-  source-dirs: src
-  exposed-modules:
-    - Data.ProtoLens.Combinators
-  dependencies:
-    - data-default-class >= 0.0 && < 0.2
-    - transformers >= 0.4 && < 0.6
-
-tests:
-  combinators_test:
-    main: combinators_test.hs
-    source-dirs: tests
-    dependencies:
-      - HUnit
-      - base
-      - lens-family
-      - lens-family-core
-      - proto-lens
-      - proto-lens-combinators
-      - proto-lens-protoc
-      - test-framework
-      - test-framework-hunit
-    other-modules:
-      Proto.Combinators
-      Proto.Combinators_Fields
diff --git a/proto-lens-combinators/proto-lens-combinators.cabal b/proto-lens-combinators/proto-lens-combinators.cabal
new file mode 100644
index 00000000..f14fd4ae
--- /dev/null
+++ b/proto-lens-combinators/proto-lens-combinators.cabal
@@ -0,0 +1,65 @@
+name:           proto-lens-combinators
+version:        0.1.0.10
+synopsis:       Utilities functions to proto-lens.
+description:    Useful things for working with protos.
+category:       Data
+homepage:       https://github.com/google/proto-lens#readme
+bug-reports:    https://github.com/google/proto-lens/issues
+author:         Zie Weaver
+maintainer:     zearen+protolens@google.com
+copyright:      Google Inc.
+license:        BSD3
+license-file:   LICENSE
+build-type:     Custom
+cabal-version:  >= 1.24
+extra-source-files:
+    Changelog.md
+    tests/combinators.proto
+
+source-repository head
+  type: git
+  location: https://github.com/google/proto-lens
+  subdir: proto-lens-combinators
+
+custom-setup
+  setup-depends:
+      Cabal
+    , base >=4.8 && <4.12
+    , proto-lens-protoc ==0.3.*
+
+library
+  exposed-modules:
+      Data.ProtoLens.Combinators
+  other-modules:
+      Paths_proto_lens_combinators
+  hs-source-dirs:
+      src
+  build-depends:
+      base >=4.8 && <4.12
+    , data-default-class >=0.0 && <0.2
+    , lens-family ==1.2.*
+    , proto-lens-protoc ==0.3.*
+    , transformers >=0.4 && <0.6
+  default-language: Haskell2010
+
+test-suite combinators_test
+  type: exitcode-stdio-1.0
+  main-is: combinators_test.hs
+  other-modules:
+      Paths_proto_lens_combinators
+      Proto.Combinators Proto.Combinators_Fields
+  autogen-modules:
+      Proto.Combinators Proto.Combinators_Fields
+  hs-source-dirs:
+      tests
+  build-depends:
+      HUnit
+    , base
+    , lens-family
+    , lens-family-core
+    , proto-lens
+    , proto-lens-combinators
+    , proto-lens-protoc
+    , test-framework
+    , test-framework-hunit
+  default-language: Haskell2010
diff --git a/proto-lens-discrimination/package.yaml b/proto-lens-discrimination/package.yaml
deleted file mode 100644
index b365c01f..00000000
--- a/proto-lens-discrimination/package.yaml
+++ /dev/null
@@ -1,56 +0,0 @@
-name: proto-lens-discrimination
-version: '0.1.1.0'
-synopsis: Support for using proto-lens types with http://hackage.haskell.org/package/discrimination.
-description: >
-  Reflection-based implementations of Sort for proto-lens'
-  generated types.
-category: Data
-author: Andrew Pritchard
-maintainer: awpr+protolens@google.com
-copyright: Google Inc.
-license: BSD3
-github: google/proto-lens/proto-lens-discrimination
-extra-source-files:
-  - tests/*.proto
-
-custom-setup:
-  dependencies:
-    - base >= 4.8 && < 4.12
-    - Cabal
-    - proto-lens-protoc == 0.3.*
-
-dependencies:
-  - base >= 4.8 && < 4.12
-  - data-default >= 0.5 && < 0.8
-  - bytestring == 0.10.*
-  - contravariant >= 1.3 && < 1.5
-  - containers >= 0.5 && < 0.6
-  - discrimination >= 0.3 && < 0.4
-  - discrimination-ieee754 == 0.1.*
-  - lens-family == 1.2.*
-  - proto-lens >= 0.3 && < 0.4
-  - proto-lens-protoc >= 0.3 && < 0.4
-  - text == 1.2.*
-
-library:
-  source-dirs: src
-  exposed-modules:
-    - Data.ProtoLens.Sort
-    - Data.ProtoLens.Group
-    - Data.ProtoLens.Discrimination
-
-tests:
-
-  discrimination_test:
-    main: disc_test.hs
-    source-dirs: tests
-    dependencies:
-      - HUnit >= 1.3 && < 1.7
-      - proto-lens-arbitrary >= 0.1 && < 0.2
-      - proto-lens-discrimination
-      - test-framework == 0.8.*
-      - test-framework-hunit == 0.3.*
-      - test-framework-quickcheck2 == 0.3.*
-    other-modules:
-      - Proto.Enum
-      - Proto.Enum_Fields
diff --git a/proto-lens-discrimination/proto-lens-discrimination.cabal b/proto-lens-discrimination/proto-lens-discrimination.cabal
new file mode 100644
index 00000000..5a5b3e0d
--- /dev/null
+++ b/proto-lens-discrimination/proto-lens-discrimination.cabal
@@ -0,0 +1,81 @@
+name:           proto-lens-discrimination
+version:        0.1.1.0
+synopsis:       Support for using proto-lens types with http://hackage.haskell.org/package/discrimination.
+description:    Reflection-based implementations of Sort for proto-lens' generated types.
+category:       Data
+homepage:       https://github.com/google/proto-lens#readme
+bug-reports:    https://github.com/google/proto-lens/issues
+author:         Andrew Pritchard
+maintainer:     awpr+protolens@google.com
+copyright:      Google Inc.
+license:        BSD3
+license-file:   LICENSE
+build-type:     Custom
+cabal-version:  >= 1.24
+extra-source-files:
+    tests/enum.proto
+
+source-repository head
+  type: git
+  location: https://github.com/google/proto-lens
+  subdir: proto-lens-discrimination
+
+custom-setup
+  setup-depends:
+      Cabal
+    , base >=4.8 && <4.12
+    , proto-lens-protoc ==0.3.*
+
+library
+  exposed-modules:
+      Data.ProtoLens.Sort
+      Data.ProtoLens.Group
+      Data.ProtoLens.Discrimination
+  other-modules:
+      Paths_proto_lens_discrimination
+  hs-source-dirs:
+      src
+  build-depends:
+      base >=4.8 && <4.12
+    , bytestring ==0.10.*
+    , containers >=0.5 && <0.6
+    , contravariant >=1.3 && <1.5
+    , data-default >=0.5 && <0.8
+    , discrimination >=0.3 && <0.4
+    , discrimination-ieee754 ==0.1.*
+    , lens-family ==1.2.*
+    , proto-lens >=0.3 && <0.4
+    , proto-lens-protoc >=0.3 && <0.4
+    , text ==1.2.*
+  default-language: Haskell2010
+
+test-suite discrimination_test
+  type: exitcode-stdio-1.0
+  main-is: disc_test.hs
+  other-modules:
+      Proto.Enum
+      Proto.Enum_Fields
+  autogen-modules:
+      Proto.Enum
+      Proto.Enum_Fields
+  hs-source-dirs:
+      tests
+  build-depends:
+      HUnit >=1.3 && <1.7
+    , base >=4.8 && <4.12
+    , bytestring ==0.10.*
+    , containers >=0.5 && <0.6
+    , contravariant >=1.3 && <1.5
+    , data-default >=0.5 && <0.8
+    , discrimination >=0.3 && <0.4
+    , discrimination-ieee754 ==0.1.*
+    , lens-family ==1.2.*
+    , proto-lens >=0.3 && <0.4
+    , proto-lens-arbitrary >=0.1 && <0.2
+    , proto-lens-discrimination
+    , proto-lens-protoc >=0.3 && <0.4
+    , test-framework ==0.8.*
+    , test-framework-hunit ==0.3.*
+    , test-framework-quickcheck2 ==0.3.*
+    , text ==1.2.*
+  default-language: Haskell2010
diff --git a/proto-lens-protobuf-types/package.yaml b/proto-lens-protobuf-types/package.yaml
deleted file mode 100644
index 367e03ea..00000000
--- a/proto-lens-protobuf-types/package.yaml
+++ /dev/null
@@ -1,44 +0,0 @@
-name: proto-lens-protobuf-types
-version: '0.3.0.1'
-synopsis: Basic protocol buffer message types.
-description: >
-  This package provides bindings standard protocol message types,
-  for use with the proto-lens library.
-category: Data
-author: Judah Jacobson
-maintainer: proto-lens@googlegroups.com
-copyright: Google Inc.
-license: BSD3
-github: google/proto-lens/proto-lens-protobuf-types
-extra-source-files:
-  - Changelog.md
-  - proto-src/google/protobuf/any.proto
-  - proto-src/google/protobuf/duration.proto
-  - proto-src/google/protobuf/wrappers.proto
-  - proto-src/google/protobuf/timestamp.proto
-
-custom-setup:
-  dependencies:
-    - base >= 4.8 && < 4.12
-    - Cabal
-    - proto-lens-protoc == 0.3.*
-
-dependencies:
-  - base >= 4.8 && < 4.12
-  - lens-family
-  - proto-lens == 0.3.*
-  - proto-lens-protoc == 0.3.*
-  - text == 1.2.*
-
-library:
-  source-dirs: src
-  exposed-modules:
-    - Data.ProtoLens.Any
-    - Proto.Google.Protobuf.Any
-    - Proto.Google.Protobuf.Any_Fields
-    - Proto.Google.Protobuf.Duration
-    - Proto.Google.Protobuf.Duration_Fields
-    - Proto.Google.Protobuf.Wrappers
-    - Proto.Google.Protobuf.Wrappers_Fields
-    - Proto.Google.Protobuf.Timestamp
-    - Proto.Google.Protobuf.Timestamp_Fields
diff --git a/proto-lens-protobuf-types/proto-lens-protobuf-types.cabal b/proto-lens-protobuf-types/proto-lens-protobuf-types.cabal
new file mode 100644
index 00000000..7ce66891
--- /dev/null
+++ b/proto-lens-protobuf-types/proto-lens-protobuf-types.cabal
@@ -0,0 +1,61 @@
+name:           proto-lens-protobuf-types
+version:        0.3.0.1
+synopsis:       Basic protocol buffer message types.
+description:    This package provides bindings standard protocol message types, for use with the proto-lens library.
+category:       Data
+homepage:       https://github.com/google/proto-lens#readme
+bug-reports:    https://github.com/google/proto-lens/issues
+author:         Judah Jacobson
+maintainer:     proto-lens@googlegroups.com
+copyright:      Google Inc.
+license:        BSD3
+license-file:   LICENSE
+build-type:     Custom
+cabal-version:  >= 1.24
+extra-source-files:
+    Changelog.md
+    proto-src/google/protobuf/any.proto
+    proto-src/google/protobuf/duration.proto
+    proto-src/google/protobuf/timestamp.proto
+    proto-src/google/protobuf/wrappers.proto
+
+source-repository head
+  type: git
+  location: https://github.com/google/proto-lens
+  subdir: proto-lens-protobuf-types
+
+custom-setup
+  setup-depends:
+      Cabal
+    , base >=4.8 && <4.12
+    , proto-lens-protoc ==0.3.*
+
+library
+  exposed-modules:
+      Data.ProtoLens.Any
+      Proto.Google.Protobuf.Any
+      Proto.Google.Protobuf.Any_Fields
+      Proto.Google.Protobuf.Duration
+      Proto.Google.Protobuf.Duration_Fields
+      Proto.Google.Protobuf.Wrappers
+      Proto.Google.Protobuf.Wrappers_Fields
+      Proto.Google.Protobuf.Timestamp
+      Proto.Google.Protobuf.Timestamp_Fields
+  autogen-modules:
+      Proto.Google.Protobuf.Any
+      Proto.Google.Protobuf.Any_Fields
+      Proto.Google.Protobuf.Duration
+      Proto.Google.Protobuf.Duration_Fields
+      Proto.Google.Protobuf.Wrappers
+      Proto.Google.Protobuf.Wrappers_Fields
+      Proto.Google.Protobuf.Timestamp
+      Proto.Google.Protobuf.Timestamp_Fields
+  hs-source-dirs:
+      src
+  build-depends:
+      base >=4.8 && <4.12
+    , lens-family
+    , proto-lens ==0.3.*
+    , proto-lens-protoc ==0.3.*
+    , text ==1.2.*
+  default-language: Haskell2010
diff --git a/proto-lens-protoc/src/Data/ProtoLens/Setup.hs b/proto-lens-protoc/src/Data/ProtoLens/Setup.hs
index cb168e72..d71febb0 100644
--- a/proto-lens-protoc/src/Data/ProtoLens/Setup.hs
+++ b/proto-lens-protoc/src/Data/ProtoLens/Setup.hs
@@ -185,11 +185,16 @@ generatingSpecificProtos root getProtos hooks = hooks
     { buildHook = \p l h f -> generate l >> buildHook hooks p l h f
     , haddockHook = \p l h f -> generate l >> haddockHook hooks p l h f
     , replHook = \p l h f args -> generate l >> replHook hooks p l h f args
+#if !MIN_VERSION_Cabal(2,0,0)
+    -- Older versions of Cabal don't support the autogen-modules field.
+    -- Work around it by manually generating the modules and putting them
+    -- in a place where `cabal sdist` will pick them up.
     , sDistHook = \p maybe_l h f -> case maybe_l of
             Nothing -> error "Can't run protoc; run 'cabal configure' first."
             Just l -> do
                         generate l
                         sDistHook hooks (fudgePackageDesc l p) maybe_l h f
+#endif
     , postCopy = \a flags pkg lbi -> do
                   let verb = fromFlag $ copyVerbosity flags
                   let destDir = datadir (absoluteInstallDirs pkg lbi
diff --git a/proto-lens-tests-dep/package.yaml b/proto-lens-tests-dep/package.yaml
deleted file mode 100644
index e7057f31..00000000
--- a/proto-lens-tests-dep/package.yaml
+++ /dev/null
@@ -1,34 +0,0 @@
-name: proto-lens-tests-dep
-version: '0.1.0.1'
-synopsis: Test package dependency.
-description: >
-  This package exports a .proto file which is used by proto-lens-tests
-  to test interpackage dependencies.
-  .
-  NOTE: The test needs a new package with its own .proto files,
-  rather than using the ones in proto-lens-protobuf-types
-  (google/protobuf/*.proto), since on some systems protoc has special logic
-  and can resolve imports of those files automatically.
-category: Data
-author: Judah Jacobson
-maintainer: proto-lens@googlegroups.com
-copyright: Google Inc.
-license: BSD3
-github: google/proto-lens/proto-lens-tests-dep
-extra-source-files:
-  - protos/test-dep/foo.proto
-
-custom-setup:
-  dependencies:
-    - base
-    - Cabal
-    - proto-lens-protoc
-
-dependencies:
-  - proto-lens-protoc
-  - base
-
-library:
-  exposed-modules:
-    - Proto.TestDep.Foo
-    - Proto.TestDep.Foo_Fields
diff --git a/proto-lens-tests-dep/proto-lens-tests-dep.cabal b/proto-lens-tests-dep/proto-lens-tests-dep.cabal
new file mode 100644
index 00000000..985faa50
--- /dev/null
+++ b/proto-lens-tests-dep/proto-lens-tests-dep.cabal
@@ -0,0 +1,39 @@
+name:           proto-lens-tests-dep
+version:        0.1.0.1
+synopsis:       Test package dependency.
+description:    This package exports a .proto file which is used by proto-lens-tests to test interpackage dependencies. . NOTE: The test needs a new package with its own .proto files, rather than using the ones in proto-lens-protobuf-types (google/protobuf/*.proto), since on some systems protoc has special logic and can resolve imports of those files automatically.
+category:       Data
+homepage:       https://github.com/google/proto-lens#readme
+bug-reports:    https://github.com/google/proto-lens/issues
+author:         Judah Jacobson
+maintainer:     proto-lens@googlegroups.com
+copyright:      Google Inc.
+license:        BSD3
+license-file:   LICENSE
+build-type:     Custom
+cabal-version:  >= 1.24
+extra-source-files:
+    protos/test-dep/foo.proto
+
+source-repository head
+  type: git
+  location: https://github.com/google/proto-lens
+  subdir: proto-lens-tests-dep
+
+custom-setup
+  setup-depends:
+      Cabal
+    , base
+    , proto-lens-protoc
+
+library
+  exposed-modules:
+      Proto.TestDep.Foo
+      Proto.TestDep.Foo_Fields
+  autogen-modules:
+      Proto.TestDep.Foo
+      Proto.TestDep.Foo_Fields
+  build-depends:
+      base
+    , proto-lens-protoc
+  default-language: Haskell2010
diff --git a/release.sh b/release.sh
deleted file mode 100755
index 289c7828..00000000
--- a/release.sh
+++ /dev/null
@@ -1,21 +0,0 @@
-#!/bin/bash
-
-set -ueo pipefail
-
-cabal sandbox init
-export CABAL_SANDBOX_CONFIG=$PWD/cabal.sandbox.config
-
-for p in lens-labels proto-lens proto-lens-protoc
-do
-  (cd $p && \
-    cabal install --force-reinstall)
-done
-
-for p in proto-lens-combinators proto-lens-protobuf-types
-do
-  (cd $p && \
-    cabal install --enable-tests --enable-benchmarks --only-dependencies && \
-    cabal configure --enable-tests --enable-benchmarks && \
-    cabal sdist)
-done
-
diff --git a/travis-cabal.sh b/travis-cabal.sh
index 5be2eede..6eb46a7b 100755
--- a/travis-cabal.sh
+++ b/travis-cabal.sh
@@ -12,7 +12,11 @@ chmod +x $HOME/.local/bin/hpack
 # List all the packages in this repo.  Put certain ones first since
 # they're dependencies of the others.  (Unfortunately, "stack query" doesn't
 # give them to us in the right order.)
-PACKAGES="
+
+# All the packages that are prepared to be test-released.
+# Don't include test packages, some of which require
+# Cabal-2.0 or higher during `sdist` due to using hpack.
+PACKAGES_TO_INSTALL="
     discrimination-ieee754
     lens-labels
     proto-lens
@@ -21,12 +25,17 @@ PACKAGES="
     proto-lens-arbitrary
     proto-lens-combinators
     proto-lens-optparse
+    proto-lens-discrimination
     proto-lens-tests-dep
+"
+
+PACKAGES_TO_BUILD="
     proto-lens-tests
-    proto-lens-discrimination
     proto-lens-benchmarks
-"
-echo Building: $PACKAGES
+"""
+
+echo Installing: ${PACKAGES_TO_INSTALL}
+echo Building: ${PACKAGES_TO_BUILD}
 
 # Needed by haskell-src-exts which is a dependency of proto-lens-protoc.
 # Sadly, Cabal won't install such build-tools automatically.
@@ -35,33 +44,47 @@ cabal install happy
 # Unregister the already-installed packages, since otherwise they may
 # propagate between builds.
 # TODO: use a Cabal sandbox for this.
-for p in $PACKAGES
+for p in $PACKAGES_TO_INSTALL
 do
   echo "Unregistering $p"
   ghc-pkg unregister --force $p || true
 done
 
-for p in $PACKAGES
+function build_package () {
+  if [ -f package.yaml ]
+    # Generate the .cabal file
+    then hpack
+  fi
+  cabal clean
+  cabal install --enable-tests --force --only-dependencies
+  cabal configure --enable-tests --enable-benchmarks
+  cabal build
+}
+
+
+for p in $PACKAGES_TO_INSTALL
 do
-    echo "Cabal building $p"
+    echo "Cabal installing $p"
     (cd $p &&
-        hpack # Generate the .cabal file
-        cabal clean
-        cabal install --enable-tests --only-dependencies
-        cabal configure --enable-tests --enable-benchmarks
-        cabal build
-        cabal sdist
-        SRC_TGZ=$(cabal info . | awk '{print $2 ".tar.gz"; exit}')
-        cd dist
-        if [ -f "$SRC_TGZ" ]; then
-            cabal install --force-reinstalls "$SRC_TGZ"
-        else
-            echo "expected '$SRC_TGZ' not found"
-            exit 1
-        fi
+      build_package
+      cabal sdist
+      SRC_TGZ=$(cabal info . | awk '{print $2 ".tar.gz"; exit}')
+      cd dist
+      if [ -f "$SRC_TGZ" ]; then
+          cabal install --force-reinstalls "$SRC_TGZ"
+      else
+          echo "expected '$SRC_TGZ' not found"
+          exit 1
+      fi
     )
 done
 
+for p in $PACKAGES_TO_BUILD
+do
+  echo "Cabal building $p"
+  (cd $p && build_package)
+done
+
 # Check that "cabal repl" works on a simple test.
 cd proto-lens-tests
 # Get rid of the previous dist/autogen to make sure "cabal repl" rebuilds it.