https://autobuilder.yocto.io/pub/repro-fail/oe-reproducible-20200902-75zprz05/packages/diff-html/ From the selftest in the build https://autobuilder.yoctoproject.org/typhoon/#/builders/80/builds/1304/steps/8/logs/step2d
Most likely related to bug 14038.
Having solved bug 14038, I suspect that was the cause of this. *** This bug has been marked as a duplicate of bug 14038 ***