test-lib: dbgcat adds headers with key name

Makes it easier to track down empty files this way

1 files changed, 1 insertions, 0 deletions

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 26adfc9..2a81a58 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -64,5 +64,6 @@ rtmpfiles () {
 dbgcat () {
         id=$1
         eval '_file=$'$id
+        echo "==> $id <=="
         sed -e "s/^/$id:/" < $_file
 }