diff --git a/MANIFEST.in b/MANIFEST.in
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+# setuptools-scm defaults to including every git-tracked file in the sdist.
+# These directories are dev/branding/test assets, not needed to build or
+# install the package, and their binary contents (video, images, tif
+# fixtures) push the sdist past PyPI's 100 MB upload limit.
+prune logo
+prune tests/data