bug#23633: artanis package installation broken

[Leo Famulari]

The artanis package creates a broken directory hierarchy like this:

/gnu/store/3090pddgmcqb989jwa7888nsvpcfkzqz-artanis-0.1.2
├── etc
│   ├── artanis
│   │   ├── 205.html
│   │   ├── 301.html
│   │   ├── 400.html
│   │   ├── 401.html
│   │   ├── 403.html
│   │   ├── 404.html
│   │   ├── 405.html
│   │   ├── 408.html
│   │   ├── 500.html
│   │   ├── 502.html
│   │   ├── 503.html
│   │   ├── 504.html
│   │   └── updating.html
│   ├── artanis.conf
│   └── bash_completion.d
│       └── show-cmds.sh
└── gnu
    └── store
        └── 3090pddgmcqb989jwa7888nsvpcfkzqz-artanis-0.1.2
            ├── bin
            │   └── art
[...]

Our package definition does change of bunch of paths from the default,
but I couldn't figure out why this was happening. Any takers?