Checksum verification failure for TeX Live 2019 on macOS
koch at math.uoregon.edu
Thu May 7 17:00:44 CEST 2020
I have a possible explanation (but am too busy today to check this out). The date you list for mactex-basictex is October 11, 2019. That is long after we built the release 2019 packages.
In 2019 at the Apple Developer Conference in June, Apple announced that install packages for Catalina would have to be notarized, and all binary applications inside would have to adopt a "hardened runtime." This requirement was not really enforced in Catalina until fairly recently and old legacy install packages work fine even today. But I didn't know that in June, so I started working on hardened runtimes and later in 2019 I released new test install packages which met the requirements. It looks like you mixed one of these later test releases with tlnet-final.
The 2020 MacTeX releases are all notarized and Apple is enforcing the requirement for these recent packages.
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