On 2021-01-24 at 17:57:13, Jason Pyeron wrote:
> $ gpg --recv-keys 96AFE6CB
> gpg: requesting key 96AFE6CB from hkp server keys.gnupg.net
> gpg: key 713660A7: "Junio C Hamano <gitster@pobox.com>" 59 new signatures
> gpg: key 713660A7: "Junio C Hamano <gitster@pobox.com>" 2 new subkeys
> gpg: no ultimately trusted keys found
> gpg: Total number processed: 1
> gpg:            new subkeys: 2
> gpg:         new signatures: 59
> 
> $ gpg --verify -v git-2.30.0.tar.sign git-2.30.0.tar.gz
> gpg: Signature made Mon Dec 28 01:12:30 2020 EST using RSA key ID 96AFE6CB
> gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
> gpg: NOTE: signature key B3F7CAC9 expired Sun Jul 26 13:41:42 2020 EDT
> gpg: using subkey 96AFE6CB instead of primary key 713660A7
> gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
> gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
> gpg: NOTE: signature key B3F7CAC9 expired Sun Jul 26 13:41:42 2020 EDT
> gpg: using PGP trust model
> gpg: BAD signature from "Junio C Hamano <gitster@pobox.com>"
> gpg: binary signature, digest algorithm SHA256

The signature is bad because it's over the uncompressed .tar, not the
.tar.gz.  There is also a .tar.xz and the signature is the same.  You
therefore need to uncompress it first with gunzip.

> $ gpg --list-keys -v 96AFE6CB
> gpg: using PGP trust model
> gpg: NOTE: signature key 96AFE6CB expired Sun Jul 26 13:41:24 2020 EDT
> gpg: NOTE: signature key B3F7CAC9 expired Sun Jul 26 13:41:42 2020 EDT
> pub   4096R/713660A7 2011-10-01
> uid                  Junio C Hamano <gitster@pobox.com>
> uid                  Junio C Hamano <junio@pobox.com>
> uid                  Junio C Hamano <jch@google.com>
> sub   4096R/96AFE6CB 2011-10-03 [expired: 2020-07-26]
> sub   4096R/833262C4 2011-10-01
> sub   4096R/B3F7CAC9 2014-09-20 [expired: 2020-07-26]
> 
> It is possible that Junio forgot to push his refreshed public key.

Yes, I think that's the case.
-- 
brian m. carlson (he/him or they/them)
Houston, Texas, US