ci: surface the OTP 27 cover failure for diagnosis

Author: gilbertwong96

.github/workflows/ci.yml

@@ -74,8 +74,8 @@ jobs:
         env:
           MIX_ENV: test
         run: |
-          mix test --cover > /tmp/cover.log 2>&1
-          tail -6 /tmp/cover.log
+          set -o pipefail
+          mix test --cover 2>&1 | tee /tmp/cover.log | tail -20
 
       - name: Extract total coverage
         id: total

mix.exs

@@ -16,7 +16,6 @@ defmodule LovelyMermaid.MixProject do
       # Quality gates
       dialyzer: [plt_add_apps: [:mix]],
 
-
       # Package
       description: "Render Mermaid diagrams as Unicode box-drawing art for terminals",
       package: package(),