Add ghc-head to the github CI

.github/workflows/packcheck.yml

@@ -68,7 +68,7 @@ jobs:
       # ------------------------------------------------------------------------
       CABAL_CHECK_RELAX: y
       CABAL_HACKAGE_MIRROR: "hackage.haskell.org:http://hackage.fpcomplete.com"
-      CABAL_PROJECT: "cabal.project"
+      CABAL_PROJECT: ${{ matrix.cabal_project }}
 
       # ------------------------------------------------------------------------
       # Where to find the required tools
@@ -110,19 +110,29 @@ jobs:
         # Adding any element to the list will increase the number of matrix
         # elements proportional to the cross product.
         include:
+
+          - name: ci
+            command: cabal
+            runner: ubuntu-latest
+            ghc_version: head
+            cabal_project: cabal.project.ghc-head
+
           - name: ci
             command: cabal
             runner: ubuntu-latest
             ghc_version: 9.8.1
+            cabal_project: cabal.project
 
           - name: ci
             command: stack
             runner: ubuntu-latest
+            cabal_project: cabal.project
 
           - name: ci
             ghc_version: 9.8.1
             command: cabal
             runner: macos-latest
+            cabal_project: cabal.project
 
           - name: ci
             command: hlint

cabal.project.ghc-head

@@ -0,0 +1,18 @@
+-- See head.hackage:
+-- info at https://ghc.gitlab.haskell.org/head.hackage/
+-- source at https://gitlab.haskell.org/ghc/head.hackage/
+
+packages: packcheck.cabal
+
+repository head.hackage.ghc.haskell.org
+   url: https://ghc.gitlab.haskell.org/head.hackage/
+   secure: True
+   key-threshold: 3
+   root-keys:
+       f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+       26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+       7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+
+active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+
+allow-newer: all

packcheck.cabal

@@ -4,7 +4,7 @@ synopsis:           Universal build and CI testing for Haskell packages
 description:
   This package contains a universal CI/build script @packcheck.sh@ and config
   files designed such that you can just copy over
-  @.github\/workflows/packcheck.yml@, @appveyor.yml@ or @.circleci/config.yml@ 
+  @.github\/workflows/packcheck.yml@, @appveyor.yml@ or @.circleci/config.yml@
   to your package repo and your package is CI ready
   in a jiffy.  You can build and test packages on local machine as well. For
   local testing, copy @packcheck.sh@ to your local machine, put it in your
@@ -54,6 +54,7 @@ extra-source-files:
     appveyor.yml
     cabal.project.coveralls
     cabal.project
+    cabal.project.ghc-head
     packcheck.sh
     packcheck-safe.sh
     packcheck-remote.sh

packcheck.sh

@@ -940,6 +940,10 @@ ghcup_install() {
     #$GHCUP_PATH set $tool $tool_ver
   fi
 
+  # This is a workaround for a bug in ghcup. See,
+  # https://github.com/actions/runner-images/issues/7061#issuecomment-1422639889
+  rm -f /usr/local/.ghcup/cache/ghcup-0.0.8.yaml
+
   if test "$tool" = "ghc"
   then
     run_verbose_errexit ghcup install ghc $GHCUP_GHC_OPTIONS $tool_ver