diff --git a/.github/workflows/selftest.macos-13.yml b/.github/workflows/selftest.macos-13.yml
index ae42cfd..25a2d6d 100644
--- a/.github/workflows/selftest.macos-13.yml
+++ b/.github/workflows/selftest.macos-13.yml
@@ -5,7 +5,7 @@ on:
     - cron: 0 0 1 * *
   push:
     branches:
-      - selftest
+      - update
 jobs:
   build:
     name: ${{ matrix.os }} / GHC ${{ matrix.ghc }}
@@ -21,58 +21,9 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - macos-13
         ghc:
-          - 7.10.3
-          - 8.0.2
-          - 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
-          - 9.8.1
           - 9.8.2
-          - 9.8.4
-          - 9.10.1
diff --git a/.github/workflows/selftest.macos-14.yml b/.github/workflows/selftest.macos-14.yml
index d0bd0b0..7ce50ad 100644
--- a/.github/workflows/selftest.macos-14.yml
+++ b/.github/workflows/selftest.macos-14.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - macos-14
diff --git a/.github/workflows/selftest.macos-15.yml b/.github/workflows/selftest.macos-15.yml
index b90909c..90f5c02 100644
--- a/.github/workflows/selftest.macos-15.yml
+++ b/.github/workflows/selftest.macos-15.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - macos-15
diff --git a/.github/workflows/selftest.ubuntu-20.04.yml b/.github/workflows/selftest.ubuntu-20.04.yml
index 6702c17..ec150bf 100644
--- a/.github/workflows/selftest.ubuntu-20.04.yml
+++ b/.github/workflows/selftest.ubuntu-20.04.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - ubuntu-20.04
diff --git a/.github/workflows/selftest.ubuntu-22.04.yml b/.github/workflows/selftest.ubuntu-22.04.yml
index 0c2761a..846d662 100644
--- a/.github/workflows/selftest.ubuntu-22.04.yml
+++ b/.github/workflows/selftest.ubuntu-22.04.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - ubuntu-22.04
diff --git a/.github/workflows/selftest.ubuntu-24.04.yml b/.github/workflows/selftest.ubuntu-24.04.yml
index b7ec1ef..86bfacf 100644
--- a/.github/workflows/selftest.ubuntu-24.04.yml
+++ b/.github/workflows/selftest.ubuntu-24.04.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - ubuntu-24.04
diff --git a/.github/workflows/selftest.windows-2019.yml b/.github/workflows/selftest.windows-2019.yml
index d23e9ed..4b03c56 100644
--- a/.github/workflows/selftest.windows-2019.yml
+++ b/.github/workflows/selftest.windows-2019.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - windows-2019
diff --git a/.github/workflows/selftest.windows-2022.yml b/.github/workflows/selftest.windows-2022.yml
index 7f34b7c..28a53a8 100644
--- a/.github/workflows/selftest.windows-2022.yml
+++ b/.github/workflows/selftest.windows-2022.yml
@@ -21,6 +21,7 @@ jobs:
       - run: cabal install alex
       - run: alex --version
     strategy:
+      fail-fast: false
       matrix:
         os:
           - windows-2022
diff --git a/README.md b/README.md
index 87b13bc..bf8b538 100644
--- a/README.md
+++ b/README.md
@@ -1,56 +1,56 @@
 |                          | `ubuntu-20.04` | `ubuntu-22.04` | `ubuntu-24.04` | `macos-13` | `macos-14` | `macos-15` | `windows-2019` | `windows-2022` |
 | :----------------------- | :------------: | :------------: | :------------: | :--------: | :--------: | :--------: | :------------: | :------------: |
-| `latest` `9.10` `9.10.1` |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.8` `9.8.4`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `latest` `9.10` `9.10.1` |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.8` `9.8.4`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
 | `9.8.2`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.8.1`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.6` `9.6.6`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.6.5`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.6.4`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.6.3`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.6.2`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.6.1`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.4` `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` `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` `9.0.2`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.0.1`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10` `8.10.7`          |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10.6`                 |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10.5`                 |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10.4`                 |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10.3`                 |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10.2`                 |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.10.1`                 |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.8` `8.8.4`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.8.3`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       ❌       |
-| `8.8.2`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.8.1`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.6` `8.6.5`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.6.4`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.6.3`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.6.2`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.6.1`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.4` `8.4.4`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.4.3`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.4.2`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.4.1`                  |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.2` `8.2.2`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `8.0` `8.0.2`            |       🟢       |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `7.10` `7.10.3`          |       🟢       |       ❌       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.8.1`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.6` `9.6.6`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.6.5`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.6.4`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.6.3`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.6.2`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.6.1`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.4` `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` `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` `9.0.2`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.0.1`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10` `8.10.7`          |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10.6`                 |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10.5`                 |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10.4`                 |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10.3`                 |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10.2`                 |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.10.1`                 |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.8` `8.8.4`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.8.3`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       ❌       |
+| `8.8.2`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.8.1`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.6` `8.6.5`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.6.4`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.6.3`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.6.2`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.6.1`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.4` `8.4.4`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.4.3`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.4.2`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.4.1`                  |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.2` `8.2.2`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `8.0` `8.0.2`            |       🟢       |       🟢       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `7.10` `7.10.3`          |       🟢       |       ❌       |       🟢       |     ❌     |     🟢     |     🟢     |       🟢       |       🟢       |
 | `7.4` `7.4.2`            |       🟢       |       ❌       |       ❌       |     ❌     |     ❌     |     ❌     |       ❌       |       ❌       |
 | `7.2` `7.2.2`            |       🟢       |       ❌       |       ❌       |     ❌     |     ❌     |     ❌     |       ❌       |       ❌       |
 | `7.0` `7.0.4`            |       🟢       |       ❌       |       ❌       |     ❌     |     ❌     |     ❌     |       ❌       |       ❌       |
diff --git a/dist/index.js b/dist/index.js
index 6bad9e4..1ff0335 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -105,10 +105,28 @@ var __importStar = (this && this.__importStar) || function (mod) {
     return result;
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.list = exports.install = void 0;
+exports.list = exports.install = exports.ensure = void 0;
 const core = __importStar(__nccwpck_require__(186));
 const exec_1 = __nccwpck_require__(514);
 const resolve_1 = __nccwpck_require__(778);
+const io_1 = __nccwpck_require__(436);
+async function ensure() {
+    if (!await (0, io_1.which)('ghcup')) {
+        await (0, exec_1.exec)('brew install ghcup');
+        const home = process.env['HOME'];
+        if (home) {
+            core.addPath(home + '/.ghcup/bin/');
+        }
+    }
+    if (!await (0, io_1.which)('cabal')) {
+        await (0, exec_1.exec)('ghcup install cabal latest --set');
+        const result = await (0, exec_1.getExecOutput)('cabal', ['path', '-v0', '--installdir'], {
+            silent: true,
+        });
+        core.addPath(result.stdout.trim());
+    }
+}
+exports.ensure = ensure;
 async function install(version) {
     const older804 = (0, resolve_1.compareVersions)(version, '8.4') == -1;
     const ncursesRequired = older804 && process.env['ImageOS'] == 'ubuntu22';
@@ -119,7 +137,6 @@ async function install(version) {
     }
     await core.group('ghcup install', async () => {
         await (0, exec_1.exec)(`ghcup install ghc ${version} --set`);
-        core.addPath('$HOME/.ghcup/bin');
     });
 }
 exports.install = install;
@@ -174,8 +191,8 @@ const ghcup = __importStar(__nccwpck_require__(474));
 const resolve_1 = __nccwpck_require__(778);
 async function main() {
     try {
+        await ghcup.ensure();
         await workaroundRunnerImageIssue7061();
-        await addCabalBinToPath();
         const requested = core.getInput('ghc-version');
         const version = await ensure(requested);
         core.setOutput('ghc-version', version);
@@ -198,12 +215,6 @@ async function workaroundRunnerImageIssue7061() {
         }
     });
 }
-async function addCabalBinToPath() {
-    const home = process.env['HOME'];
-    if (home) {
-        core.addPath(home + '/.cabal/bin/');
-    }
-}
 async function ensure(requested) {
     const resolved = await (0, resolve_1.resolve)(requested);
     await install(resolved);
@@ -275,6 +286,7 @@ var __importStar = (this && this.__importStar) || function (mod) {
 Object.defineProperty(exports, "__esModule", ({ value: true }));
 exports.installed = exports.resolve = exports.resolveVersion = exports.compareVersions = void 0;
 const exec_1 = __nccwpck_require__(514);
+const io_1 = __nccwpck_require__(436);
 const apt = __importStar(__nccwpck_require__(911));
 const ghcup = __importStar(__nccwpck_require__(474));
 function compareVersions(a, b) {
@@ -307,19 +319,27 @@ function resolveVersion(requested, versions) {
     }
 }
 exports.resolveVersion = resolveVersion;
+async function resolveFoo(requested) {
+    const versions = new Set([...apt.versions(), ...await ghcup.list()]);
+    return resolveVersion(requested, versions);
+}
 async function resolve(requested) {
     const systemVersion = await installed();
     const aptVersions = apt.versions();
     let version;
     if (requested === 'system') {
-        version = systemVersion;
+        if (systemVersion) {
+            version = systemVersion;
+        }
+        else {
+            version = await resolveFoo('latest');
+        }
     }
     else if (apt.versions().has(requested)) {
         version = requested;
     }
     else {
-        const versions = new Set([...apt.versions(), ...await ghcup.list()]);
-        version = resolveVersion(requested, versions);
+        version = await resolveFoo(requested);
     }
     if (version) {
         const source = version === systemVersion ? 'system' :
@@ -335,10 +355,15 @@ async function resolve(requested) {
 }
 exports.resolve = resolve;
 async function installed() {
-    const result = await (0, exec_1.getExecOutput)('ghc', ['--numeric-version'], {
-        silent: true,
-    });
-    return result.stdout.trim();
+    if (await (0, io_1.which)('ghc')) {
+        const result = await (0, exec_1.getExecOutput)('ghc', ['--numeric-version'], {
+            silent: true,
+        });
+        return result.stdout.trim();
+    }
+    else {
+        return undefined;
+    }
 }
 exports.installed = installed;
 
diff --git a/generate/selftest.ts b/generate/selftest.ts
index 58f253d..199ed58 100644
--- a/generate/selftest.ts
+++ b/generate/selftest.ts
@@ -19,7 +19,7 @@ export async function versionMap() {
     'ubuntu-20.04': new Set([...ppa.ubuntu20, ...ghcup]),
     'ubuntu-22.04': new Set([...ghcup].filter(v => !not_working_on_ubuntu_22_04.has(v))),
     'ubuntu-24.04': ghcup,
-    'macos-13': ghcup,
+    'macos-13': new Set(['9.8.2']),
     'macos-14': ghcup,
     'macos-15': ghcup,
     'windows-2019': ghcup,
diff --git a/src/ghcup.ts b/src/ghcup.ts
index f4bcb59..6b04e6b 100644
--- a/src/ghcup.ts
+++ b/src/ghcup.ts
@@ -1,6 +1,24 @@
 import * as core from '@actions/core';
 import { exec, getExecOutput } from '@actions/exec';
 import { compareVersions } from './resolve';
+import { which } from '@actions/io';
+
+export async function ensure() {
+  if (!await which('ghcup')) {
+    await exec('brew install ghcup');
+    const home = process.env['HOME'];
+    if (home) {
+      core.addPath(home + '/.ghcup/bin/');
+    }
+  }
+  if (!await which('cabal')) {
+    await exec('ghcup install cabal latest --set');
+    const result = await getExecOutput('cabal', ['path', '-v0', '--installdir'], {
+      silent: true,
+    });
+    core.addPath(result.stdout.trim());
+  }
+}
 
 export async function install(version: string) {
   const older804 = compareVersions(version, '8.4') == -1;
@@ -12,7 +30,6 @@ export async function install(version: string) {
   }
   await core.group('ghcup install', async () => {
     await exec(`ghcup install ghc ${version} --set`);
-    core.addPath('$HOME/.ghcup/bin');
   });
 }
 
diff --git a/src/main.ts b/src/main.ts
index 5c70559..dbb2f5f 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -8,8 +8,8 @@ import { installed, resolve, ResolvedVersion } from './resolve';
 
 async function main() {
   try {
+    await ghcup.ensure();
     await workaroundRunnerImageIssue7061();
-    await addCabalBinToPath();
     const requested = core.getInput('ghc-version');
     const version = await ensure(requested);
     core.setOutput('ghc-version', version);
@@ -32,13 +32,6 @@ async function workaroundRunnerImageIssue7061() {
   });
 }
 
-async function addCabalBinToPath() {
-  const home = process.env['HOME'];
-  if (home) {
-    core.addPath(home + '/.cabal/bin/');
-  }
-}
-
 async function ensure(requested: string): Promise<string> {
   const resolved = await resolve(requested);
   await install(resolved);
diff --git a/src/resolve.ts b/src/resolve.ts
index 43eeb0b..34c3473 100644
--- a/src/resolve.ts
+++ b/src/resolve.ts
@@ -1,4 +1,5 @@
 import { getExecOutput } from '@actions/exec';
+import { which } from '@actions/io';
 
 import * as apt from './apt';
 import * as ghcup from './ghcup';
@@ -39,18 +40,26 @@ export type ResolvedVersion = {
   source: 'system' | 'apt' | 'ghcup';
 };
 
+async function resolveFoo(requested: string): Promise<string | undefined> {
+  const versions = new Set([...apt.versions(), ...await ghcup.list()]);
+  return resolveVersion(requested, versions);
+}
+
 export async function resolve(requested: string): Promise<ResolvedVersion> {
   const systemVersion = await installed();
   const aptVersions = apt.versions();
 
   let version;
   if (requested === 'system') {
-    version = systemVersion;
+    if (systemVersion) {
+      version = systemVersion;
+    } else {
+      version = await resolveFoo('latest');
+    }
   } else if (apt.versions().has(requested)) {
     version = requested;
   } else {
-    const versions = new Set([...apt.versions(), ...await ghcup.list()]);
-    version = resolveVersion(requested, versions);
+    version = await resolveFoo(requested);
   }
 
   if (version) {
@@ -65,9 +74,13 @@ export async function resolve(requested: string): Promise<ResolvedVersion> {
   }
 }
 
-export async function installed(): Promise<string> {
-  const result = await getExecOutput('ghc', ['--numeric-version'], {
-    silent: true,
-  });
-  return result.stdout.trim();
+export async function installed(): Promise<string | undefined> {
+  if (await which('ghc')) {
+    const result = await getExecOutput('ghc', ['--numeric-version'], {
+      silent: true,
+    });
+    return result.stdout.trim();
+  } else {
+    return undefined;
+  }
 }