docker: cache-bust the cadgenbench @main install

ADD the GitHub commits endpoint for the tracked ref before the pip
install so BuildKit invalidates the cached layer whenever main moves;
otherwise @main would stay pinned to the first build's HEAD. No-op when
CADGENBENCH_SHA is a fixed commit SHA.

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -42,6 +42,12 @@ RUN pip install --no-cache-dir -r /tmp/requirements.txt \
 # to a specific commit SHA at the v1 release so published scores are
 # reproducible (see space-setup/post-gt-swap.md Stage F).
 ARG CADGENBENCH_SHA=main
+# Cache-bust the install below whenever the tracked ref moves: the
+# GitHub commits endpoint's response changes with each new commit on
+# `main`, so BuildKit re-fetches and invalidates the cached pip layer.
+# Without it, `@main` would stay pinned to whatever `main` was at first
+# build. Stable (a no-op) when CADGENBENCH_SHA is a fixed commit SHA.
+ADD https://api.github.com/repos/huggingface/cadgenbench/commits/${CADGENBENCH_SHA} /tmp/cadgenbench.commit
 RUN pip install --no-cache-dir \
         "cadgenbench @ git+https://github.com/huggingface/cadgenbench.git@${CADGENBENCH_SHA}"