diff --git a/hledger-api/hledger-api.cabal b/hledger-api/hledger-api.cabal
index 4dfd0f60f..a40f6e516 100644
--- a/hledger-api/hledger-api.cabal
+++ b/hledger-api/hledger-api.cabal
@@ -1,8 +1,10 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 79786a2effbdf3258e88ee988c7cbbab5951550bac768bab7cbd1c9080fd198d
+-- hash: a7796b2c57190b1a9a60ea235d0249aeff513bd31e171803183335d0065c6bdf
 
 name:           hledger-api
 version:        1.11.99
@@ -26,15 +28,14 @@ license:        GPL-3
 license-file:   LICENSE
 tested-with:    GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
     CHANGES
+    README
     examples/01.html
     examples/02.html
     hledger-api.1
-    hledger-api.info
     hledger-api.txt
-    README
+    hledger-api.info
 
 source-repository head
   type: git
diff --git a/hledger-lib/hledger-lib.cabal b/hledger-lib/hledger-lib.cabal
index 26e4135d7..bbd5543d8 100644
--- a/hledger-lib/hledger-lib.cabal
+++ b/hledger-lib/hledger-lib.cabal
@@ -1,8 +1,10 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 22a6817292c6f2d53f935ce939331bea06b956c94b4e391d198760704ec294b3
+-- hash: 90a6e00affee2de34a1d34c52c01445d207316b5114a60e0f890697053dacc00
 
 name:           hledger-lib
 version:        1.11.99
@@ -25,22 +27,21 @@ license:        GPL-3
 license-file:   LICENSE
 tested-with:    GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
     CHANGES
-    hledger_csv.5
-    hledger_csv.info
-    hledger_csv.txt
-    hledger_journal.5
-    hledger_journal.info
-    hledger_journal.txt
-    hledger_timeclock.5
-    hledger_timeclock.info
-    hledger_timeclock.txt
-    hledger_timedot.5
-    hledger_timedot.info
-    hledger_timedot.txt
     README
+    hledger_csv.5
+    hledger_csv.txt
+    hledger_csv.info
+    hledger_journal.5
+    hledger_journal.txt
+    hledger_journal.info
+    hledger_timedot.5
+    hledger_timedot.txt
+    hledger_timedot.info
+    hledger_timeclock.5
+    hledger_timeclock.txt
+    hledger_timeclock.info
 
 source-repository head
   type: git
diff --git a/hledger-ui/hledger-ui.cabal b/hledger-ui/hledger-ui.cabal
index e5d4ae20f..e488d1c1a 100644
--- a/hledger-ui/hledger-ui.cabal
+++ b/hledger-ui/hledger-ui.cabal
@@ -1,8 +1,10 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: fb0ef2467dcf115f1fc7a6f9d7781ec6912e7545a52921968067666c1747fff4
+-- hash: 0732dd6182685765b68edb5dd5009c0f24bc3367b4c51720b0aa2a07ecfca483
 
 name:           hledger-ui
 version:        1.11.99
@@ -27,13 +29,12 @@ license:        GPL-3
 license-file:   LICENSE
 tested-with:    GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
     CHANGES
-    hledger-ui.1
-    hledger-ui.info
-    hledger-ui.txt
     README
+    hledger-ui.1
+    hledger-ui.txt
+    hledger-ui.info
 
 source-repository head
   type: git
diff --git a/hledger-web/hledger-web.cabal b/hledger-web/hledger-web.cabal
index b02326fb4..7b3fbdbf6 100644
--- a/hledger-web/hledger-web.cabal
+++ b/hledger-web/hledger-web.cabal
@@ -1,8 +1,10 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 443e668fdd64fb57d1d9488224df0bc6ee4e796bcc75f81655a92850ff809d34
+-- hash: 7ec1692d7c6c7546bdd9fd2109f7ef00f02082133a0d732ff552d8099d3cbd7c
 
 name:           hledger-web
 version:        1.11.99
@@ -27,25 +29,21 @@ license:        GPL-3
 license-file:   LICENSE
 tested-with:    GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
     CHANGES
+    README
     config/favicon.ico
     config/keter.yaml
     config/robots.txt
     config/routes
     config/settings.yml
-    hledger-web.1
-    hledger-web.info
-    hledger-web.txt
-    README
     static/css/bootstrap-datepicker.standalone.min.css
     static/css/bootstrap-theme.css
-    static/css/bootstrap-theme.css.map
     static/css/bootstrap-theme.min.css
     static/css/bootstrap.css
-    static/css/bootstrap.css.map
     static/css/bootstrap.min.css
+    static/css/bootstrap-theme.css.map
+    static/css/bootstrap.css.map
     static/fonts/glyphicons-halflings-regular.eot
     static/fonts/glyphicons-halflings-regular.svg
     static/fonts/glyphicons-halflings-regular.ttf
@@ -106,6 +104,9 @@ extra-source-files:
     templates/manage.hamlet
     templates/register.hamlet
     templates/upload-form.hamlet
+    hledger-web.1
+    hledger-web.txt
+    hledger-web.info
 
 source-repository head
   type: git
@@ -182,6 +183,10 @@ library
     , wai-handler-launch >=1.3
     , warp
     , yaml
+  if (flag(dev)) || (flag(library-only))
+    cpp-options: -DDEVELOPMENT
+  if flag(dev)
+    ghc-options: -O0
   if impl(ghc >=8)
     ghc-options: -Wcompat -Wincomplete-uni-patterns -Wincomplete-record-updates -Wredundant-constraints
   if os(darwin) && impl(ghc < 8.0)
@@ -205,8 +210,16 @@ executable hledger-web
   build-depends:
       base
     , hledger-web
+  if (flag(dev)) || (flag(library-only))
+    cpp-options: -DDEVELOPMENT
+  if flag(dev)
+    ghc-options: -O0
   if impl(ghc >=8)
     ghc-options: -Wcompat -Wincomplete-uni-patterns -Wincomplete-record-updates -Wredundant-constraints
+  if flag(library-only)
+    buildable: False
+  if flag(threaded)
+    ghc-options: -threaded
   if os(darwin) && impl(ghc < 8.0)
     buildable: False
   default-language: Haskell2010
diff --git a/hledger/hledger.cabal b/hledger/hledger.cabal
index d32629977..17762c334 100644
--- a/hledger/hledger.cabal
+++ b/hledger/hledger.cabal
@@ -1,8 +1,10 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.0.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 78515e93d6f08be6d098bdd697b951a1577e4e71c6b24ad64cf69916d3af191c
+-- hash: 35dc218f658f30998772647d4c70f40df1cbdd8a58eb21e8283d6e417fb8c1ac
 
 name:           hledger
 version:        1.11.99
@@ -27,39 +29,38 @@ license:        GPL-3
 license-file:   LICENSE
 tested-with:    GHC==7.10.3, GHC==8.0.2, GHC==8.2.2, GHC==8.4.3
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
-    bench/10000x1000x10.journal
     CHANGES
-    embeddedfiles/hledger-api.1
-    embeddedfiles/hledger-api.info
-    embeddedfiles/hledger-api.txt
-    embeddedfiles/hledger-ui.1
-    embeddedfiles/hledger-ui.info
-    embeddedfiles/hledger-ui.txt
-    embeddedfiles/hledger-web.1
-    embeddedfiles/hledger-web.info
-    embeddedfiles/hledger-web.txt
-    embeddedfiles/hledger.1
-    embeddedfiles/hledger.info
-    embeddedfiles/hledger.txt
-    embeddedfiles/hledger_csv.5
-    embeddedfiles/hledger_csv.info
-    embeddedfiles/hledger_csv.txt
-    embeddedfiles/hledger_journal.5
-    embeddedfiles/hledger_journal.info
-    embeddedfiles/hledger_journal.txt
-    embeddedfiles/hledger_timeclock.5
-    embeddedfiles/hledger_timeclock.info
-    embeddedfiles/hledger_timeclock.txt
-    embeddedfiles/hledger_timedot.5
-    embeddedfiles/hledger_timedot.info
-    embeddedfiles/hledger_timedot.txt
-    hledger.1
-    hledger.info
-    hledger.txt
     README.md
     test/test.hs
+    bench/10000x1000x10.journal
+    hledger.1
+    hledger.txt
+    hledger.info
+    embeddedfiles/hledger.1
+    embeddedfiles/hledger.txt
+    embeddedfiles/hledger.info
+    embeddedfiles/hledger-api.1
+    embeddedfiles/hledger-api.txt
+    embeddedfiles/hledger-api.info
+    embeddedfiles/hledger-ui.1
+    embeddedfiles/hledger-ui.txt
+    embeddedfiles/hledger-ui.info
+    embeddedfiles/hledger-web.1
+    embeddedfiles/hledger-web.txt
+    embeddedfiles/hledger-web.info
+    embeddedfiles/hledger_journal.5
+    embeddedfiles/hledger_journal.txt
+    embeddedfiles/hledger_journal.info
+    embeddedfiles/hledger_csv.5
+    embeddedfiles/hledger_csv.txt
+    embeddedfiles/hledger_csv.info
+    embeddedfiles/hledger_timeclock.5
+    embeddedfiles/hledger_timeclock.txt
+    embeddedfiles/hledger_timeclock.info
+    embeddedfiles/hledger_timedot.5
+    embeddedfiles/hledger_timedot.txt
+    embeddedfiles/hledger_timedot.info
 
 source-repository head
   type: git