thodg/libgit2

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 66d8117..c8264ea 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -15,7 +15,7 @@ jobs:
       uses: actions/checkout@v2
     - name: Calculate image label
       run: |
-        cd azure-pipelines/docker && git log -1 -- ./
+        cd azure-pipelines/docker && GIT_TRACE=1 git log -1 -- ./
         echo "::set-env name=docker-label::libgit2-$(git log -1 --pretty=format:"%h" -- azure-pipelines/docker/\*)"
 #    - name: Log in to GitHub Packages
 #      run: |