Hello,

I'm on latest master:

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Generation 10   Aug 28 2020 18:19:10    (current)
    guix 95eade1
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 95eade1389beaad79f6d07c7ffeff4235424eab0

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guix build `emacs-clojure-mode` fails with this error:

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starting phase `check'
Loading /gnu/store/8w81gl56lxaylbyslzz3z32k6fxacl66-emacs-buttercup-1.23/share/emacs/site-lisp/buttercup-autoloads...
Loading /gnu/store/rc5in960n20xsb21dr3ri71mx1vswqd9-emacs-dash-2.17.0/share/emacs/site-lisp/dash-autoloads...
Loading /gnu/store/hfmbkal5jfnz0zix4iw8f2wf6zmnr39h-emacs-paredit-24/share/emacs/site-lisp/paredit-autoloads...
Loading /gnu/store/cc556b4zrqkgk8yhy9f4b354w0pqdm4p-emacs-s-1.12.0/share/emacs/site-lisp/s-autoloads...
Running tests on Emacs 27.1
Loading /tmp/guix-build-emacs-clojure-mode-5.12.0.drv-0/source/clojure-mode.el (source)...
Warning (emacs): 
clojure-mode.el:1761: All variables and subroutines might as well have a documentation string
Failing due to checkdoc warnings...
command "buttercup" failed with status 1

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It's an upstream issue and Jack Hill reported this issue 23 days ago
https://github.com/clojure-emacs/clojure-mode/issues/568.

It was emacs-clojure-mode-5.11.0, different line but same code:

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;; project.el integration
(cl-defmethod project-roots ((project (head clojure)))
  (list (cdr project)))

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I'll propose a patch as soon as I'm able.

Thanks! Gio'

-- 
Giovanni Biscuolo

Xelera IT Infrastructures