Add step summary output to CI builds, with failure logs. (#20288)

util/ci/generate_failure_markdown.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+set -e
+
+this_script="$(realpath "${BASH_SOURCE[0]}")"
+script_dir="$(realpath "$(dirname "$this_script")")"
+qmk_firmware_dir="$(realpath "$script_dir/../../")"
+
+dump_failure_info() {
+    local failure_file="$1"
+    local keyboard=$(cat "$failure_file" | grep 'CI Metadata: KEYBOARD=' | cut -d= -f2)
+    local keymap=$(cat "$failure_file" | grep 'CI Metadata: KEYMAP=' | cut -d= -f2)
+    echo "## ${keyboard}:${keymap}"
+    echo "\`\`\`"
+    cat "$failure_file" | sed -e $'s/\x1b\[[0-9;]*m//g' | grep -v "CI Metadata:" | grep -vP "(Entering|Leaving) directory"
+    echo "\`\`\`"
+}
+
+for failure_file in $(find "$qmk_firmware_dir/.build" -name 'failed.log.*' | sort); do
+    dump_failure_info "$failure_file"
+done