The mecanism has changed since last release, see https://guix.gnu.org/manual/devel/en/html_node/Building-from-Git.html#Building-from-Git

(Note "devel" in the URL, it corresponds to the latest master). We now use "guix git authenticate" to authenticate the repository.

On 2020年8月21日 11:43:54 GMT-04:00, tchrzcz--- via Bug reports for GNU Guix <bug-guix@gnu.org> wrote:
>Hello,
>
>https://guix.gnu.org/manual/en/html_node/Building-from-Git.html#Building-from-Git
>says:
>
>"How do you ensure that you obtained a genuine copy of the repository?
>Guix itself provides a tool to authenticate your checkout, but you must
>first make sure this tool is genuine in order to “bootstrap” the trust
>chain. To do that, run:
>
>git verify-commit `git log --format=%H build-aux/git-authenticate.scm`"
>
>1. When I run the command, I get the following error:
>
>"fatal: ambiguous argument 'build-aux/git-authenticate.scm': unknown
>revision or path not in the working tree.
>Use '--' to separate paths from revisions, like this:
>'git <command> [<revision>...] -- [<file>...]'
>usage: git verify-commit [-v | --verbose] <commit>...
>
>    -v, --verbose         print commit contents
>    --raw                 print raw gpg status output"
>
>
>2. So I looked for "git-authenticate.scm" with 'find' and got two
>results:
>./tests/git-authenticate.scm
>./guix/git-authenticate.scm
>
>3. These two are different files, sizes don't match, 'diff' outputs a
>lot of stuff.
>
>4. I searched for "git-authenticate" in NEWS, HACKING and README and
>didn't find anything.
>
>5. Then I figured I'd look in Git commits and found these two:
>
>https://git.savannah.gnu.org/cgit/guix.git/commit/?id=41f443c90af57f9537eccb1a1a45c6e11b377a32
>"Add (guix git-authenticate)."
>https://git.savannah.gnu.org/cgit/guix.git/commit/?id=96bf434c70c4346c6402658d3ec57ef64a8e521e
>"maint: Remove 'build-aux/git-authenticate.scm'."
>
>I'm not fluent in Git, GPG, nor Guile. Do I just run the command with
>"guix/git-authenticate.scm" instead of
>"build-aux/git-authenticate.scm"?
>
>Regards,
>tchrzcz