Hello,

I found that BitBucket redirects to the login page:

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix build --no-substitutes java-snakeyaml
[...]
Starting download of /gnu/store/j4isfqwkfx1c8nhr3jry0rkdq8r39ckc-java-snakeyaml-1.18.tar.gz
From https://bitbucket.org/asomov/snakeyaml/get/v1.18.tar.gz...
following redirection to `https://bitbucket.org/account/signin/?next=/asomov/snakeyaml/get/v1.18.tar.gz'...
following redirection to `https://id.atlassian.com/login?application=bitbucket&continue=https%3A%2F%2Fbitbucket.org%2Faccount%2Fsignin%2F%3FredirectCount%3D1%26next%3D%252Fasomov%252Fsnakeyaml%252Fget%252Fv1.18.tar.gz'...
downloading from https://bitbucket.org/asomov/snakeyaml/get/v1.18.tar.gz ...

sha256 hash mismatch for /gnu/store/j4isfqwkfx1c8nhr3jry0rkdq8r39ckc-java-snakeyaml-1.18.tar.gz:
  expected hash: 0474cqcv46zgv9bhms2vgawakq1vyj0hp3h3f1bfys46msia90bh
  actual hash:   11x0dw0l9a7kj55qzr8hzc0fzh44xwwpcjarik10wxyg446wra1j
hash mismatch for store item '/gnu/store/j4isfqwkfx1c8nhr3jry0rkdq8r39ckc-java-snakeyaml-1.18.tar.gz'
build of /gnu/store/f5h57jakhnray2iivbviih8hhyr8far8-java-snakeyaml-1.18.tar.gz.drv failed
View build log at '/var/log/guix/drvs/f5/h57jakhnray2iivbviih8hhyr8far8-java-snakeyaml-1.18.tar.gz.drv.bz2'.
cannot build derivation `/gnu/store/da59l9m79qxqqlhp7z9r7yvh4ysdvgpg-java-snakeyaml-1.18.drv': 1 dependencies couldn't be built
guix build: error: build of `/gnu/store/da59l9m79qxqqlhp7z9r7yvh4ysdvgpg-java-snakeyaml-1.18.drv' failed
--8<---------------cut here---------------end--------------->8---

So I replaced the BitBucket URI with GitHub mirror URI.

'guix lint' complains about the lack of upstream releases because
there's no git tags for each release. It's really unfortunate situation
but that's how the project's upstream is organized.  :-/

Thanks,

- Artyom