bug#28659: v0.13: guix pull fails; libgit2-0.26.0 and 0.25.1 content hashes fail

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

I've modified the script to sort the packages it prints:
--8<---------------cut here---------------start------------->8---
-    (for-each (lambda (p)
-		(format #t "~a~%" (package-name p)))
-	      packages)))
+    (for-each (lambda (name)
+		(format #t "~a~%" name))
+	      (sort (map package-name packages) string<?))))
--8<---------------cut here---------------end--------------->8---

and compared it to the list here: https://github.com/Homebrew/homebrew-core/issues/18044

If we can trust the Homebrew list to be extensive, it seems we got
lucky; there's only one affected package that we share which is
yaml-cpp. Here's how it fails on our side:

--8<---------------cut here---------------start------------->8---
guix build -S --no-substitutes yaml-cpp
The following derivation will be built:
   /gnu/store/mlap8jmadirnbii6sppb6vj9x56s8azw-yaml-cpp-0.5.3.tar.gz.drv
@ build-started /gnu/store/mlap8jmadirnbii6sppb6vj9x56s8azw-yaml-cpp-0.5.3.tar.gz.drv - x86_64-linux /var/log/guix/drvs/ml//ap8jmadirnbii6sppb6vj9x56s8azw-yaml-cpp-0.5.3.tar.gz.drv.bz2

Starting download of /gnu/store/qwflwafrzjbr2b7dy4nv18nxykghhmnk-yaml-cpp-0.5.3.tar.gz
From https://github.com/jbeder/yaml-cpp/archive/yaml-cpp-0.5.3.tar.gz...
following redirection to `https://codeload.github.com/jbeder/yaml-cpp/tar.gz/yaml-cpp-0.5.3'...
 ...p-0.5.3                                  1.7MiB/s 00:01 | 1.9MiB transferred
sha256 hash mismatch for output path `/gnu/store/qwflwafrzjbr2b7dy4nv18nxykghhmnk-yaml-cpp-0.5.3.tar.gz'
  expected: 1vk6pjh0f5k6jwk2sszb9z5169whmiha9ainbdpa1arxlkq7v3b6
  actual:   1ck7jk0wjfigrf4cgcjqsir4yp1s6vamhhxhpsgfvs46pgm5pk6y
@ build-failed /gnu/store/mlap8jmadirnbii6sppb6vj9x56s8azw-yaml-cpp-0.5.3.tar.gz.drv - 1 sha256 hash mismatch for output path `/gnu/store/qwflwafrzjbr2b7dy4nv18nxykghhmnk-yaml-cpp-0.5.3.tar.gz'
  expected: 1vk6pjh0f5k6jwk2sszb9z5169whmiha9ainbdpa1arxlkq7v3b6
  actual:   1ck7jk0wjfigrf4cgcjqsir4yp1s6vamhhxhpsgfvs46pgm5pk6y
guix build: error: build failed: build of
`/gnu/store/mlap8jmadirnbii6sppb6vj9x56s8azw-yaml-cpp-0.5.3.tar.gz.drv'
failed
--8<---------------cut here---------------end--------------->8---

Maxim