CI: install gnudiff and enable `Test_diffmode` on macos-14 runner again (#14056)

Signed-off-by: rhysd <lin90162@yahoo.co.jp>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 677630baa22163ff5408e53dd94a36cfecb50f4f..a641ef563e9ebc57c927269ce0c4a55c37c608f8 100644 (file)
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -373,6 +373,11 @@ jobs:
           "${SRCDIR}"/vim -u NONE -i NONE --not-a-term -esNX -V1 -S ci/if_ver-1.vim -c quit
           "${SRCDIR}"/vim -u NONE -i NONE --not-a-term -esNX -V1 -S ci/if_ver-2.vim -c quit
 
+      - name: Install packages for testing
+        run: |
+          # Apple diff is broken. Use GNU diff instead. See #14032.
+          brew install diffutils
+
       - name: Test
         timeout-minutes: 20
         run: |