Thanks for the review and comments. Below is a revised patch.
It seemed to work ok here.
--------
* gnu/packages/statistics.scm (r)[arguments]: make and install info files
diff --git a/gnu/packages/statistics.scm b/gnu/packages/statistics.scm
index 91d988e..35355f7 100644
--- a/gnu/packages/statistics.scm
+++ b/gnu/packages/statistics.scm
@@ -58,11 +58,23 @@
(assoc-ref %outputs "out")
"/lib/R/lib"))
#:phases
- (alist-cons-before
- 'check 'set-timezone
- ;; Some tests require the timezone to be set.
- (lambda _ (setenv "TZ" "UTC"))
- %standard-phases)
+ (modify-phases %standard-phases
+ (add-before 'check 'set-timezone
+ ;; Some tests require the timezone to be set.
+ (lambda _ (setenv "TZ" "UTC")))
+ (add-after 'install 'install-info
+ (lambda* (#:key inputs outputs #:allow-other-keys)
+ (let ((out (assoc-ref outputs "out")))
+ (and (zero? (system* "make" "info"))
+ (let ((infodir (string-append out "/share/info")))
+ (mkdir-p infodir)
+ (chdir "./doc/manual")
+ (for-each (lambda (info)
+ (copy-file
+ info
+ (string-append infodir "/" info)))
+ (find-files "." "\\.info$"))
+ #t))))))
#:configure-flags
'("--with-blas"
"--with-lapack"
