diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 9937ab13..11e0be59 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -162,7 +162,7 @@ jobs:
       - name: cache (tools)
         uses: actions/cache/restore@v4
         with:
-          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-e88c451c
+          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-2e5ae02c
           path: ~/.haskell-ci-tools
       - name: install cabal-plan
         run: |
@@ -190,7 +190,7 @@ jobs:
         if: always()
         uses: actions/cache/save@v4
         with:
-          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-e88c451c
+          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-2e5ae02c
           path: ~/.haskell-ci-tools
       - name: checkout
         uses: actions/checkout@v4
diff --git a/fixtures/all-versions.bash b/fixtures/all-versions.bash
index ba9fb62c..7d7ec123 100644
--- a/fixtures/all-versions.bash
+++ b/fixtures/all-versions.bash
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 #!/bin/bash
 # shellcheck disable=SC2086,SC2016,SC2046
 # REGENDATA ["bash","all-versions.project"]
@@ -21,7 +21,7 @@ fi
 
 CFG_CABAL_STORE_CACHE=""
 CFG_CABAL_REPO_CACHE=""
-CFG_JOBS="9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
+CFG_JOBS="9.14.1 9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
 CFG_CABAL_UPDATE=false
 
 SCRIPT_NAME=$(basename "$0")
diff --git a/fixtures/all-versions.github b/fixtures/all-versions.github
index 9534a003..1bd9da51 100644
--- a/fixtures/all-versions.github
+++ b/fixtures/all-versions.github
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 # This GitHub workflow config has been generated by a script via
 #
 #   haskell-ci 'github' 'all-versions.project'
@@ -28,6 +28,11 @@ jobs:
     strategy:
       matrix:
         include:
+          - compiler: ghc-9.14.0.20250819
+            compilerKind: ghc
+            compilerVersion: 9.14.0.20250819
+            setup-method: ghcup-prerelease
+            allow-failure: false
           - compiler: ghc-9.12.2
             compilerKind: ghc
             compilerVersion: 9.12.2
@@ -345,7 +350,22 @@ jobs:
       - name: Install GHC (GHCup vanilla)
         if: matrix.setup-method == 'ghcup-vanilla'
         run: |
-          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.8.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.9.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
           HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
           HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
           HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
@@ -366,7 +386,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
+          if [ $((! GHCJSARITH && HCNUMVER >= 91400)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
         env:
           HCKIND: ${{ matrix.compilerKind }}
@@ -394,6 +414,18 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
+          if $HEADHACKAGE; then
+          cat >> $CABAL_CONFIG <<EOF
+          repository head.hackage.ghc.haskell.org
+             url: https://ghc.gitlab.haskell.org/head.hackage/
+             secure: True
+             root-keys: 7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+                        26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+                        f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+             key-threshold: 3
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+          EOF
+          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -449,6 +481,9 @@ jobs:
           if [ $((! GHCJSARITH && HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
+          if $HEADHACKAGE; then
+          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
+          fi
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(splitmix)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
diff --git a/fixtures/doctest-version.bash b/fixtures/doctest-version.bash
index e8ae6b06..cacd47f9 100644
--- a/fixtures/doctest-version.bash
+++ b/fixtures/doctest-version.bash
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 #!/bin/bash
 # shellcheck disable=SC2086,SC2016,SC2046
 # REGENDATA ["--doctest","--doctest-version=^>=0.20","bash","doctest-version.project"]
@@ -21,7 +21,7 @@ fi
 
 CFG_CABAL_STORE_CACHE=""
 CFG_CABAL_REPO_CACHE=""
-CFG_JOBS="9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
+CFG_JOBS="9.14.1 9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
 CFG_CABAL_UPDATE=false
 
 SCRIPT_NAME=$(basename "$0")
diff --git a/fixtures/doctest-version.github b/fixtures/doctest-version.github
index ea0153b6..e57ca1a4 100644
--- a/fixtures/doctest-version.github
+++ b/fixtures/doctest-version.github
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 # This GitHub workflow config has been generated by a script via
 #
 #   haskell-ci '--doctest' '--doctest-version=^>=0.20' 'github' 'doctest-version.project'
@@ -28,6 +28,11 @@ jobs:
     strategy:
       matrix:
         include:
+          - compiler: ghc-9.14.0.20250819
+            compilerKind: ghc
+            compilerVersion: 9.14.0.20250819
+            setup-method: ghcup-prerelease
+            allow-failure: false
           - compiler: ghc-9.12.2
             compilerKind: ghc
             compilerVersion: 9.12.2
@@ -345,7 +350,22 @@ jobs:
       - name: Install GHC (GHCup vanilla)
         if: matrix.setup-method == 'ghcup-vanilla'
         run: |
-          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.8.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.9.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
           HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
           HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
           HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
@@ -366,7 +386,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
+          if [ $((! GHCJSARITH && HCNUMVER >= 91400)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
         env:
           HCKIND: ${{ matrix.compilerKind }}
@@ -394,6 +414,18 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
+          if $HEADHACKAGE; then
+          cat >> $CABAL_CONFIG <<EOF
+          repository head.hackage.ghc.haskell.org
+             url: https://ghc.gitlab.haskell.org/head.hackage/
+             secure: True
+             root-keys: 7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+                        26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+                        f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+             key-threshold: 3
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+          EOF
+          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -410,7 +442,7 @@ jobs:
       - name: cache (tools)
         uses: actions/cache/restore@v4
         with:
-          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-7adc43de
+          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-7f722948
           path: ~/.haskell-ci-tools
       - name: install cabal-plan
         run: |
@@ -429,7 +461,7 @@ jobs:
         if: always()
         uses: actions/cache/save@v4
         with:
-          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-7adc43de
+          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-7f722948
           path: ~/.haskell-ci-tools
       - name: checkout
         uses: actions/checkout@v4
@@ -464,6 +496,9 @@ jobs:
           if [ $((! GHCJSARITH && HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
+          if $HEADHACKAGE; then
+          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
+          fi
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(splitmix)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
diff --git a/fixtures/doctest.bash b/fixtures/doctest.bash
index 887ad6f8..1c118f31 100644
--- a/fixtures/doctest.bash
+++ b/fixtures/doctest.bash
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 #!/bin/bash
 # shellcheck disable=SC2086,SC2016,SC2046
 # REGENDATA ["--doctest","bash","doctest.project"]
@@ -21,7 +21,7 @@ fi
 
 CFG_CABAL_STORE_CACHE=""
 CFG_CABAL_REPO_CACHE=""
-CFG_JOBS="9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
+CFG_JOBS="9.14.1 9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
 CFG_CABAL_UPDATE=false
 
 SCRIPT_NAME=$(basename "$0")
diff --git a/fixtures/doctest.github b/fixtures/doctest.github
index ea5d1802..9d4645f0 100644
--- a/fixtures/doctest.github
+++ b/fixtures/doctest.github
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 # This GitHub workflow config has been generated by a script via
 #
 #   haskell-ci '--doctest' 'github' 'doctest.project'
@@ -28,6 +28,11 @@ jobs:
     strategy:
       matrix:
         include:
+          - compiler: ghc-9.14.0.20250819
+            compilerKind: ghc
+            compilerVersion: 9.14.0.20250819
+            setup-method: ghcup-prerelease
+            allow-failure: false
           - compiler: ghc-9.12.2
             compilerKind: ghc
             compilerVersion: 9.12.2
@@ -345,7 +350,22 @@ jobs:
       - name: Install GHC (GHCup vanilla)
         if: matrix.setup-method == 'ghcup-vanilla'
         run: |
-          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.8.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.9.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
           HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
           HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
           HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
@@ -366,7 +386,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
+          if [ $((! GHCJSARITH && HCNUMVER >= 91400)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
         env:
           HCKIND: ${{ matrix.compilerKind }}
@@ -394,6 +414,18 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
+          if $HEADHACKAGE; then
+          cat >> $CABAL_CONFIG <<EOF
+          repository head.hackage.ghc.haskell.org
+             url: https://ghc.gitlab.haskell.org/head.hackage/
+             secure: True
+             root-keys: 7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+                        26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+                        f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+             key-threshold: 3
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+          EOF
+          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -410,7 +442,7 @@ jobs:
       - name: cache (tools)
         uses: actions/cache/restore@v4
         with:
-          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-cc3c62c0
+          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-9d25091b
           path: ~/.haskell-ci-tools
       - name: install cabal-plan
         run: |
@@ -429,7 +461,7 @@ jobs:
         if: always()
         uses: actions/cache/save@v4
         with:
-          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-cc3c62c0
+          key: ${{ runner.os }}-${{ matrix.compiler }}-tools-9d25091b
           path: ~/.haskell-ci-tools
       - name: checkout
         uses: actions/checkout@v4
@@ -464,6 +496,9 @@ jobs:
           if [ $((! GHCJSARITH && HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
+          if $HEADHACKAGE; then
+          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
+          fi
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(splitmix)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
diff --git a/fixtures/empty-line.github b/fixtures/empty-line.github
index 88ad50c8..a5ef2989 100644
--- a/fixtures/empty-line.github
+++ b/fixtures/empty-line.github
@@ -177,6 +177,21 @@ jobs:
           HCKIND: ${{ matrix.compilerKind }}
           HCNAME: ${{ matrix.compiler }}
           HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
       - name: Set PATH and environment variables
         run: |
           echo "$HOME/.cabal/bin" >> $GITHUB_PATH
diff --git a/fixtures/enabled-jobs.bash b/fixtures/enabled-jobs.bash
index bff8be6a..0f27e229 100644
--- a/fixtures/enabled-jobs.bash
+++ b/fixtures/enabled-jobs.bash
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating Bash script for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 #!/bin/bash
 # shellcheck disable=SC2086,SC2016,SC2046
 # REGENDATA ["--enabled-jobs=>=8","bash","enabled-jobs.project"]
@@ -21,7 +21,7 @@ fi
 
 CFG_CABAL_STORE_CACHE=""
 CFG_CABAL_REPO_CACHE=""
-CFG_JOBS="9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
+CFG_JOBS="9.14.1 9.12.2 9.12.1 9.10.2 9.10.1 9.8.4 9.8.3 9.8.2 9.8.1 9.6.7 9.6.6 9.6.5 9.6.4 9.6.3 9.6.2 9.6.1 9.4.8 9.4.7 9.4.6 9.4.5 9.4.4 9.4.3 9.4.2 9.4.1 9.2.8 9.2.7 9.2.6 9.2.5 9.2.4 9.2.3 9.2.2 9.2.1 9.0.2 9.0.1 8.10.7 8.10.6 8.10.5 8.10.4 8.10.3 8.10.2 8.10.1 8.8.4 8.8.3 8.8.2 8.8.1 8.6.5 8.6.4 8.6.3 8.6.2 8.6.1 8.4.4 8.4.3 8.4.2 8.4.1 8.2.2 8.2.1 8.0.2 8.0.1"
 CFG_CABAL_UPDATE=false
 
 SCRIPT_NAME=$(basename "$0")
diff --git a/fixtures/enabled-jobs.github b/fixtures/enabled-jobs.github
index 6f62a7c9..320811d6 100644
--- a/fixtures/enabled-jobs.github
+++ b/fixtures/enabled-jobs.github
@@ -1,5 +1,5 @@
 # SUCCESS
-# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 ghcjs-8.4
+# *INFO* Generating GitHub config for testing for GHC versions: 8.0.1 8.0.2 8.2.1 8.2.2 8.4.1 8.4.2 8.4.3 8.4.4 8.6.1 8.6.2 8.6.3 8.6.4 8.6.5 8.8.1 8.8.2 8.8.3 8.8.4 8.10.1 8.10.2 8.10.3 8.10.4 8.10.5 8.10.6 8.10.7 9.0.1 9.0.2 9.2.1 9.2.2 9.2.3 9.2.4 9.2.5 9.2.6 9.2.7 9.2.8 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.4.6 9.4.7 9.4.8 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 9.6.7 9.8.1 9.8.2 9.8.3 9.8.4 9.10.1 9.10.2 9.12.1 9.12.2 9.14.1 ghcjs-8.4
 # This GitHub workflow config has been generated by a script via
 #
 #   haskell-ci '--enabled-jobs=>=8' 'github' 'enabled-jobs.project'
@@ -28,6 +28,11 @@ jobs:
     strategy:
       matrix:
         include:
+          - compiler: ghc-9.14.0.20250819
+            compilerKind: ghc
+            compilerVersion: 9.14.0.20250819
+            setup-method: ghcup-prerelease
+            allow-failure: false
           - compiler: ghc-9.12.2
             compilerKind: ghc
             compilerVersion: 9.12.2
@@ -345,7 +350,22 @@ jobs:
       - name: Install GHC (GHCup vanilla)
         if: matrix.setup-method == 'ghcup-vanilla'
         run: |
-          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.8.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          "$HOME/.ghcup/bin/ghcup" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.9.yaml install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
           HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
           HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
           HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
@@ -366,7 +386,7 @@ jobs:
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
           echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV"
-          echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
+          if [ $((! GHCJSARITH && HCNUMVER >= 91400)) -ne 0 ] ; then echo "HEADHACKAGE=true" >> "$GITHUB_ENV" ; else echo "HEADHACKAGE=false" >> "$GITHUB_ENV" ; fi
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
         env:
           HCKIND: ${{ matrix.compilerKind }}
@@ -394,6 +414,18 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
+          if $HEADHACKAGE; then
+          cat >> $CABAL_CONFIG <<EOF
+          repository head.hackage.ghc.haskell.org
+             url: https://ghc.gitlab.haskell.org/head.hackage/
+             secure: True
+             root-keys: 7541f32a4ccca4f97aea3b22f5e593ba2c0267546016b992dfadcd2fe944e55d
+                        26021a13b401500c8eb2761ca95c61f2d625bfef951b939a8124ed12ecf07329
+                        f76d08be13e9a61a377a85e2fb63f4c5435d40f8feb3e12eb05905edb8cdea89
+             key-threshold: 3
+          active-repositories: hackage.haskell.org, head.hackage.ghc.haskell.org:override
+          EOF
+          fi
           cat >> $CABAL_CONFIG <<EOF
           program-default-options
             ghc-options: $GHCJOBS +RTS -M3G -RTS
@@ -449,6 +481,9 @@ jobs:
           if [ $((! GHCJSARITH && HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
+          if $HEADHACKAGE; then
+          echo "allow-newer: $($HCPKG list --simple-output | sed -E 's/([a-zA-Z-]+)-[0-9.]+/*:\1,/g')" >> cabal.project
+          fi
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(splitmix)$/; }' >> cabal.project.local
           cat cabal.project
           cat cabal.project.local
diff --git a/fixtures/messy.github b/fixtures/messy.github
index aae961c8..1d82d571 100644
--- a/fixtures/messy.github
+++ b/fixtures/messy.github
@@ -178,6 +178,21 @@ jobs:
           HCKIND: ${{ matrix.compilerKind }}
           HCNAME: ${{ matrix.compiler }}
           HCVER: ${{ matrix.compilerVersion }}
+      - name: Install GHC (GHCup prerelease)
+        if: matrix.setup-method == 'ghcup-prerelease'
+        run: |
+          "$HOME/.ghcup/bin/ghcup" config add-release-channel prereleases
+          "$HOME/.ghcup/bin/ghcup" install ghc "$HCVER" || (cat "$HOME"/.ghcup/logs/*.* && false)
+          HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
+          HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
+          HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
+          echo "HC=$HC" >> "$GITHUB_ENV"
+          echo "HCPKG=$HCPKG" >> "$GITHUB_ENV"
+          echo "HADDOCK=$HADDOCK" >> "$GITHUB_ENV"
+        env:
+          HCKIND: ${{ matrix.compilerKind }}
+          HCNAME: ${{ matrix.compiler }}
+          HCVER: ${{ matrix.compilerVersion }}
       - name: Set PATH and environment variables
         run: |
           echo "$HOME/.cabal/bin" >> $GITHUB_PATH
diff --git a/haskell-ci.cabal b/haskell-ci.cabal
index f9d8c466..a4b32a77 100644
--- a/haskell-ci.cabal
+++ b/haskell-ci.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.2
 name:               haskell-ci
-version:            0.19.20250801
+version:            0.19.20250821
 synopsis:           Haskell CI script generator
 description:
   Script generator (@haskell-ci@) for
diff --git a/src/HaskellCI/Compiler.hs b/src/HaskellCI/Compiler.hs
index 6295bccd..2009e935 100644
--- a/src/HaskellCI/Compiler.hs
+++ b/src/HaskellCI/Compiler.hs
@@ -146,6 +146,7 @@ knownGhcVersions = fmap mkVersion
     , [9,8,1],  [9,8,2],  [9,8,3], [9,8,4]
     , [9,10,1], [9,10,2]
     , [9,12,1], [9,12,2]
+    , [9,14,1]
     ]
 
 knownGhcjsVersions :: [Version]
diff --git a/src/HaskellCI/Config/History.hs b/src/HaskellCI/Config/History.hs
index 8758564a..ec92ca8d 100644
--- a/src/HaskellCI/Config/History.hs
+++ b/src/HaskellCI/Config/History.hs
@@ -89,6 +89,14 @@ configHistory =
         & field @"cfgErrorIncompletePatterns" .~ C.orLaterVersion (C.mkVersion [9,0])
     , ver 0 19 20250801 := \cfg -> cfg
         & field @"cfgCabalInstallVersion" ?~ C.mkVersion [3,16,0,0]
+    , ver 0 19 20250801 := \cfg -> cfg
+        & field @"cfgVersionMapping" .~ Map.singleton (mkVersion [9,14,1]) (mkVersion [9,14,0,20250819])
+        & field @"cfgSetupMethods" .~ PerSetupMethod
+            { hvrPpa          = C.noVersion
+            , ghcup           = invertVersionRange (C.withinVersion (C.mkVersion [9,8,3])) /\ C.earlierVersion (C.mkVersion [9,14])
+            , ghcupVanilla    = C.withinVersion (C.mkVersion [9,8,3])
+            , ghcupPrerelease = C.orLaterVersion (C.mkVersion [9,14])
+            }
     ]
   where
     ver x y z = [x, y, z]
diff --git a/src/HaskellCI/GitHub.hs b/src/HaskellCI/GitHub.hs
index 56dcc496..b340070a 100644
--- a/src/HaskellCI/GitHub.hs
+++ b/src/HaskellCI/GitHub.hs
@@ -152,7 +152,7 @@ makeGitHub _argv config@Config {..} gitconfig prj jobs@JobVersions {..} = do
             tell_env "CABAL" $ "$HOME/.ghcup/bin/cabal-" ++ cabalFullVer ++ " -vnormal+nowrap"
 
         when cabalPrerelease $ githubRun "Install cabal-install (prerelease)" $ do
-            sh "\"$HOME/.ghcup/bin/ghcup\" config add-release-channel https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-prereleases-0.0.8.yaml;"
+            sh "\"$HOME/.ghcup/bin/ghcup\" config add-release-channel prereleases;"
             sh $ "\"$HOME/.ghcup/bin/ghcup\" install cabal " ++ cabalFullVer ++ " || (cat \"$HOME\"/.ghcup/logs/*.* && false)"
             tell_env "CABAL" $ "$HOME/.ghcup/bin/cabal-" ++ cabalFullVer ++ " -vnormal+nowrap"
 
@@ -184,11 +184,11 @@ makeGitHub _argv config@Config {..} gitconfig prj jobs@JobVersions {..} = do
             ghcupGhcEnv
 
         whenWithinGhcRange (index cfgSetupMethods GHCUPvanilla) $ githubRunIf' "Install GHC (GHCup vanilla)" "matrix.setup-method == 'ghcup-vanilla'" envEnv $ do
-            sh $ "\"$HOME/.ghcup/bin/ghcup\" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.8.yaml install ghc \"$HCVER\" || (cat \"$HOME\"/.ghcup/logs/*.* && false)"
+            sh $ "\"$HOME/.ghcup/bin/ghcup\" -s https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-vanilla-0.0.9.yaml install ghc \"$HCVER\" || (cat \"$HOME\"/.ghcup/logs/*.* && false)"
             ghcupGhcEnv
 
         whenWithinGhcRange (index cfgSetupMethods GHCUPprerelease) $ githubRunIf' "Install GHC (GHCup prerelease)" "matrix.setup-method == 'ghcup-prerelease'" envEnv $ do
-            sh "\"$HOME/.ghcup/bin/ghcup\" config add-release-channel https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-prereleases-0.0.8.yaml;"
+            sh "\"$HOME/.ghcup/bin/ghcup\" config add-release-channel prereleases"
             sh $ "\"$HOME/.ghcup/bin/ghcup\" install ghc \"$HCVER\" || (cat \"$HOME\"/.ghcup/logs/*.* && false)"
             ghcupGhcEnv