diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 45cb9c09..e7deef33 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -111,7 +111,6 @@ jobs:
           echo "CABAL_CONFIG=$HOME/.cabal/config" >> "$GITHUB_ENV"
           HCDIR=/opt/$HCKIND/$HCVER
           HC=$("$HOME/.ghcup/bin/ghcup" whereis ghc "$HCVER")
-          echo "$HOME/.ghcup/bin" >> "$GITHUB_PATH"
           HCPKG=$(echo "$HC" | sed 's#ghc$#ghc-pkg#')
           HADDOCK=$(echo "$HC" | sed 's#ghc$#haddock#')
           echo "HC=$HC" >> "$GITHUB_ENV"
@@ -263,9 +262,7 @@ jobs:
           $CABAL v2-build $ARG_COMPILER $ARG_TESTS $ARG_BENCH all --write-ghc-environment-files=always
       - name: tests
         run: |
-          export HAPPY=$HOME/.cabal/bin/happy
-          export HC
-          export CABAL
+          export HAPPY=$($CABAL list-bin happy)
           $CABAL v2-test $ARG_COMPILER $ARG_TESTS $ARG_BENCH all --test-show-details=direct
       - name: cabal check
         run: |
diff --git a/DEVELOPER.md b/DEVELOPER.md
index 96776d27..47c6dc78 100644
--- a/DEVELOPER.md
+++ b/DEVELOPER.md
@@ -3,57 +3,9 @@ This document holds some useful information for developing Happy.
 CI on GitHub Actions
 ====================
 
-2021-07-14
+2024-07-15
+----------
 
 The GHC workflow file `.github/workflows/haskell-ci.yml` is generated by:
 
     haskell-ci regenerate
-    patch --input=.github/haskell-ci.patch .github/workflows/haskell-ci.yml
-
-The patch introduces happy specifics to the build and test process that
-are not covered by a vanilla instance of the haskell-ci workflow.
-
-When new GHC versions become available, CI can be updated by
-
- - adding these versions to the `tested-with` field in `happy.cabal`
-   (possibly removing obsolete minor versions)
-
- - generate the `haskell-ci.yml` by the steps above.
-
-This should work as long as `haskell-ci` does not change its generated
-workflow too much.  Otherwise, the patch might not apply cleanly and
-the workflow has to be patched manually.
-
-2023-02-06 Updating to a new version of Haskell-CI
---------------------------------------------------
-
-1. Install Haskell-CI from its source repo:
-
-        pushd /tmp
-        git clone https://github.com/haskell-CI/haskell-ci.git
-        cd haskell-ci
-        cabal install
-        popd
-
-2. Update the `tested-with` fields in the `.cabal` files.
-
-3. Follow the instructions to regenerate the Haskell CI workflow, which are:
-
-        haskell-ci regenerate
-        patch --input=.github/haskell-ci.patch .github/workflows/haskell-ci.yml
-
-If some hunks fail to apply in the last step, the patch as to be updated.
-
-4. Apply the remaining hunks manually.
-
-5. Save the patched workflow, regenerate the original workflow, regenerate the patch
-
-        cp .github/workflows/haskell-ci.yml .github/workflows/haskell-ci.yml-patched
-        haskell-ci regenerate
-        diff -u .github/workflows/haskell-ci.yml .github/workflows/haskell-ci.yml-patched > .github/haskell-ci.patch
-
-6. Now the patch will apply cleanly.
-
-        patch --input=.github/haskell-ci.patch .github/workflows/haskell-ci.yml
-
-7. Commit the updated files (no extra files need to be committed).
diff --git a/tests/Makefile b/tests/Makefile
index 399126d1..26afd345 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -12,9 +12,9 @@
 # [2021-07-14, PR #196](https://github.com/haskell/happy/pull/196)
 #
 ifndef HAPPY
-HAPPY=$(shell which happy)
+HAPPY=$(shell cabal list-bin happy)
 ifeq "$(filter $(dir $(shell pwd))%,$(HAPPY))" ""
-HAPPY=../dist/build/happy/happy
+$(error Environment variable $$HAPPY not set and `cabal list-bin happy` did not succeed. Cannot run testsuite.)
 endif
 endif