Testing Python's difflib to look at html output for a spec, both with json and text.
spack spec --json python@2.7 > spec1.json
spack spec --json python@3.9 > spec2.json
spack spec python@2.7 > spec1.txt
spack spec python@3.9 > spec2.txt
python diff.py -m spec1.txt spec2.txt > index.html
python diff.py -m spec1.json spec2.json > json.html
The json is nice!