[PATCH] Fix CRAN updater for single URLs.

[Ricardo Wurmus]

Hi Guix,

currently, the CRAN updater crashes on trying to find the latest release
of r-qtl:

~~~~~
rwurmus in guix: ./pre-inst-env guix refresh -t cran
warning: failed to install locale: Invalid argument
;;; note: source file /home/rwurmus/code/guix/gnu/packages/bioinformatics.scm
;;;       newer than compiled 
/home/rwurmus/code/guix/gnu/packages/bioinformatics.go
;;; found fresh local cache at 
/home/rwurmus/.cache/guile/ccache/2.0-LE-8-2.0/home/rwurmus/code/guix/gnu/packages/bioinformatics.scm.go
gnu/packages/web.scm:3018:13: r-htmltools would be upgraded from 0.2.6 to 0.3
gnu/packages/web.scm:3060:13: r-curl would be upgraded from 0.9.3 to 0.9.6
gnu/packages/web.scm:2969:13: r-jsonlite would be upgraded from 0.9.17 to 0.9.19
gnu/packages/statistics.scm:1895:13: r-viridis would be upgraded from 0.3.1 to 
0.3.2
gnu/packages/statistics.scm:378:13: r-stringi would be upgraded from 0.5-5 to 
1.0-1
gnu/packages/statistics.scm:704:13: r-knitr would be upgraded from 1.11 to 
1.12.3
gnu/packages/statistics.scm:1435:13: r-rmarkdown would be upgraded from 0.8.1 
to 0.9.5
gnu/packages/statistics.scm:194:13: r-digest would be upgraded from 0.6.8 to 
0.6.9
gnu/packages/statistics.scm:856:13: r-r6 would be upgraded from 2.1.1 to 2.1.2
gnu/packages/statistics.scm:1201:13: r-git2r would be upgraded from 0.11.0 to 
0.13.1
gnu/packages/statistics.scm:1351:13: r-rcpparmadillo would be upgraded from 
0.6.200.2.0 to 0.6.500.4.0
gnu/packages/statistics.scm:1227:13: r-rstudioapi would be upgraded from 0.3.1 
to 0.5
gnu/packages/statistics.scm:1921:13: r-plotly would be upgraded from 2.0.3 to 
2.0.16
gnu/packages/statistics.scm:1745:13: r-r-methodss3 would be upgraded from 1.7.0 
to 1.7.1
gnu/packages/statistics.scm:835:13: r-testthat would be upgraded from 0.10.0 to 
0.11.0
gnu/packages/statistics.scm:563:13: r-bh would be upgraded from 1.58.0-1 to 
1.60.0-1
gnu/packages/statistics.scm:1951:13: r-hmisc would be upgraded from 3.17-1 to 
3.17-2
gnu/packages/statistics.scm:1245:13: r-devtools would be upgraded from 1.9.1 to 
1.10.0
gnu/packages/statistics.scm:295:13: r-rcpp would be upgraded from 0.12.2 to 
0.12.3
gnu/packages/statistics.scm:1871:13: r-matrixstats would be upgraded from 
0.15.0 to 0.50.1
gnu/packages/statistics.scm:1174:13: r-httr would be upgraded from 1.0.0 to 
1.1.0
gnu/packages/statistics.scm:275:13: r-munsell would be upgraded from 0.4.2 to 
0.4.3
gnu/packages/statistics.scm:1150:13: r-roxygen2 would be upgraded from 5.0.0 to 
5.0.1
gnu/packages/statistics.scm:792:13: r-memoise would be upgraded from 0.2.1 to 
1.0.0
gnu/packages/statistics.scm:1792:13: r-r-utils would be upgraded from 2.1.0 to 
2.2.0
gnu/packages/statistics.scm:1296:13: r-plotrix would be upgraded from 3.6 to 
3.6-1
gnu/packages/statistics.scm:733:13: r-microbenchmark would be upgraded from 
1.4-2 to 1.4-2.1
gnu/packages/statistics.scm:476:13: r-ggplot2 would be upgraded from 1.0.1 to 
2.0.0
gnu/packages/statistics.scm:1769:13: r-r-oo would be upgraded from 1.19.0 to 
1.20.0
gnu/packages/statistics.scm:1840:13: r-r-rsp would be upgraded from 0.20.0 to 
0.21.0
gnu/packages/bioinformatics.scm:4124:13: r-acsnminer would be upgraded from 
0.15.11 to 0.16.01.29
Backtrace:
In ice-9/boot-9.scm:
 157: 17 [catch #t #<catch-closure 25157a0> ...]
In unknown file:
   ?: 16 [apply-smob/1 #<catch-closure 25157a0>]
In ice-9/boot-9.scm:
  63: 15 [call-with-prompt prompt0 ...]
In ice-9/eval.scm:
 432: 14 [eval # #]
In ice-9/boot-9.scm:
2401: 13 [save-module-excursion #<procedure 2532940 at ice-9/boot-9.scm:4045:3 
()>]
4050: 12 [#<procedure 2532940 at ice-9/boot-9.scm:4045:3 ()>]
1724: 11 [%start-stack load-stack ...]
1729: 10 [#<procedure 254aea0 ()>]
In unknown file:
   ?: 9 [primitive-load "/home/rwurmus/code/guix/scripts/guix"]
In guix/ui.scm:
1177: 8 [run-guix-command refresh "-t" "cran"]
In ice-9/boot-9.scm:
 157: 7 [catch srfi-34 #<procedure 4ee30c0 at guix/ui.scm:413:2 ()> ...]
 157: 6 [catch system-error ...]
In srfi/srfi-1.scm:
 616: 5 [for-each #<procedure 4ee9460 at guix/scripts/refresh.scm:396:18 
(package)> ...]
In guix/scripts/refresh.scm:
 397: 4 [#<procedure 4ee9460 at guix/scripts/refresh.scm:396:18 (package)> #]
In guix/upstream.scm:
 137: 3 [package-update-path # #]
In guix/import/cran.scm:
 247: 2 [latest-cran-release "r-qtl"]
 127: 1 [fetch-description "http://cran.r-project.org/web/packages/"; #f]
In unknown file:
   ?: 0 [string-append "http://cran.r-project.org/web/packages/"; #f 
"/DESCRIPTION"]

ERROR: In procedure string-append:
ERROR: In procedure string-append: Wrong type (expecting string): #f
~~~~~

Attached is a patch to fix this.

~~ Ricardo

>From 306a74c5e615f1f4d4109974135030dfa1696ec9 Mon Sep 17 00:00:00 2001
From: Ricardo Wurmus <address@hidden>
Date: Tue, 22 Mar 2016 15:12:30 +0100
Subject: [PATCH] import: cran: Accept single URL in addition to single URL.

* guix/import/cran.scm (package->upstream-name): Match single URL in
  addition to list of URLs.
---
 guix/import/cran.scm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/guix/import/cran.scm b/guix/import/cran.scm
index f36e948..562917c 100644
--- a/guix/import/cran.scm
+++ b/guix/import/cran.scm
@@ -227,7 +227,7 @@ s-expression corresponding to that package, or #f on 
failure."
         (match (package-source package)
           ((? origin? origin)
            (match (origin-uri origin)
-             ((url rest ...)
+             ((or (? string? url) (url _ ...))
               (let ((end   (string-rindex url #\_))
                     (start (string-rindex url #\/)))
                 ;; The URL ends on
-- 
2.1.0