From 7312d6f3f3f732648cbe96cad4a454edee78ee3f Mon Sep 17 00:00:00 2001
From: Tomas Janousek <tomi@nomi.cz>
Date: Sun, 30 Oct 2022 20:53:39 +0000
Subject: [PATCH] ci: Drop GHC installation via apt

The apt repo hosting these packages has been unmaintained for quite a
while, and we've excluded ~/.stack/programs from the cache long time
ago, so we can just let stack handle the installation. It's not much
slower than installing via apt, and even if it was, some matrix jobs
need to use the slow path anyway.

Related: 9fce3805fcf2 ("ci: Use system GHC in Stack to not waste GH Actions cache space")
Related: 7d10e470d71d ("ci: Avoid caching GHC")
---
 .github/workflows/stack.yml | 29 +++++++----------------------
 1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/.github/workflows/stack.yml b/.github/workflows/stack.yml
index 526c47ff..b978f2de 100644
--- a/.github/workflows/stack.yml
+++ b/.github/workflows/stack.yml
@@ -12,26 +12,19 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - resolver: lts-12
-            ghc: 8.4.4
+          - resolver: lts-12  # GHC 8.4
             yaml: stack.yaml
-          - resolver: lts-12
-            ghc: 8.4.4
+          - resolver: lts-12  # GHC 8.4
             yaml: stack-master.yaml
-          - resolver: lts-14
-            ghc: 8.6.5
+          - resolver: lts-14  # GHC 8.6
             yaml: stack-master.yaml
-          - resolver: lts-16
-            ghc: 8.8.4
+          - resolver: lts-16  # GHC 8.8
             yaml: stack-master.yaml
-          - resolver: lts-18
-            ghc: 8.10.7
+          - resolver: lts-18  # GHC 8.10
             yaml: stack-master.yaml
-          - resolver: lts-19
-            ghc: 9.0.2
+          - resolver: lts-19  # GHC 9.0
             yaml: stack.yaml
-          - resolver: lts-19
-            ghc: 9.0.2
+          - resolver: lts-19  # GHC 9.0
             yaml: stack-master.yaml
 
     steps:
@@ -56,14 +49,6 @@ jobs:
             libxss-dev \
             #
 
-      - name: Install GHC
-        # use system ghc (if available) in stack, don't waste GH Actions cache space
-        continue-on-error: true
-        run: |
-          set -ex
-          sudo apt install -y ghc-${{ matrix.ghc }}
-          echo /opt/ghc/${{ matrix.ghc }}/bin >> $GITHUB_PATH
-
       - name: Refresh caches once a month
         id: cache-date
         # GHA writes caches on the first miss and then never updates them again;