### Please describe the problem.
No matter what I do I can't 

### What steps will reproduce the problem?
Create a repository, try to add a remote. An external disk in this case.

### What version of git-annex are you using? On what operating system?
Fedora 27

    $ cat /etc/fedora-release
    Fedora release 27 (Twenty Seven)
    $ uname -a
    Linux greger 4.14.14-300.fc27.x86_64 #1 SMP Fri Jan 19 13:19:54 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

    $ git annex version
    git-annex version: 6.20180130-g39d97867a
    build flags: Assistant Webapp Pairing S3(multipartupload)(storageclasses) WebDAV Inotify DBus DesktopNotify ConcurrentOutput TorrentParser Feeds Testsuite
    dependency versions: aws-0.17.1 bloomfilter-2.0.1.0 cryptonite-0.23 DAV-1.3.1 feed-0.3.12.0 ghc-8.0.2 http-client-0.5.7.0 persistent-sqlite-2.6.2 torrent-10000.1.1 uuid-1.3.13 yesod-1.4.5
    key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_224 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 SHA1E SHA1 MD5E MD5 WORM URL
    remote types: git gcrypt p2p S3 bup directory rsync web bittorrent webdav tahoe glacier ddar hook external
    local repository version: 5
    supported repository versions: 3 5 6
    upgrade supported from repository versions: 0 1 2 3 4 5
    operating system: linux x86_64


### Please provide any additional information below.

Debug log:

    [2018-01-31 14:46:15.670775214] main: starting assistant version 6.20180130-g39d97867a
    [2018-01-31 14:46:15.776042349] Cronner: You should enable consistency checking to protect your data. 
    (scanning...) [2018-01-31 14:46:15.988042623] Watcher: Performing startup scan
    (started...) 
    [2018-01-31 14:47:48.236476657] read: gpg ["--quiet","--trust-model","always","--with-colons","--list-secret-keys","--fixed-list-mode"]
    [2018-01-31 14:47:48.262055169] process done ExitSuccess
    [2018-01-31 14:47:51.695935824] read: git ["init","--quiet","--bare","/run/media/dxtr/archive/annex"]
    [2018-01-31 14:47:51.700278024] process done ExitSuccess
    [2018-01-31 14:47:51.700424216] read: git ["config","--null","--list"]
    [2018-01-31 14:47:51.707427206] process done ExitSuccess
    [2018-01-31 14:47:51.70868726] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","config","core.fsyncobjectfiles","true"]
    [2018-01-31 14:47:51.725766269] process done ExitSuccess
    [2018-01-31 14:47:51.728215647] read: git ["config","--null","--list"]
    [2018-01-31 14:47:51.740757992] process done ExitSuccess
    [2018-01-31 14:47:51.741434499] read: git ["config","--null","--list"]
    [2018-01-31 14:47:51.753548799] process done ExitSuccess
    [2018-01-31 14:47:51.755149461] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","show-ref","git-annex"]
    [2018-01-31 14:47:51.771911199] process done ExitFailure 1
    [2018-01-31 14:47:51.772860937] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","show-ref","--hash","refs/heads/git-annex"]
    [2018-01-31 14:47:51.789876829] process done ExitFailure 1
    [2018-01-31 14:47:51.790600261] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","show-ref","--verify","-q","origin/git-annex"]
    [2018-01-31 14:47:51.79719711] process done ExitFailure 1
    [2018-01-31 14:47:51.799141741] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","write-tree"]
    [2018-01-31 14:47:51.807820543] process done ExitSuccess
    [2018-01-31 14:47:51.809126461] chat: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","commit-tree","4b825dc642cb6eb9a060e54bf8d69288fbee4904","--no-gpg-sign"]
    [2018-01-31 14:47:51.836742843] process done ExitSuccess
    [2018-01-31 14:47:51.837688371] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","update-ref","refs/heads/git-annex","c1bd62a595ce9cb811ad353ed0d9eaf8cfcb0b30"]
    [2018-01-31 14:47:51.849598566] process done ExitSuccess
    [2018-01-31 14:47:51.850762057] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","config","annex.uuid","da4c4bf3-5b3d-47f7-98d6-040cf8094360"]
    [2018-01-31 14:47:51.855957091] process done ExitSuccess
    [2018-01-31 14:47:51.85617243] read: git ["config","--null","--list"]
    [2018-01-31 14:47:51.858450427] process done ExitSuccess
    [2018-01-31 14:47:51.860771677] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","show-ref","git-annex"]
    [2018-01-31 14:47:51.879636685] process done ExitSuccess
    [2018-01-31 14:47:51.880463945] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","show-ref","--hash","refs/heads/git-annex"]
    [2018-01-31 14:47:51.897305118] process done ExitSuccess
    [2018-01-31 14:47:51.899214969] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","log","refs/heads/git-annex..c1bd62a595ce9cb811ad353ed0d9eaf8cfcb0b30","--pretty=%H","-n1"]
    [2018-01-31 14:47:51.9105804] process done ExitSuccess
    [2018-01-31 14:47:51.912107527] chat: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","cat-file","--batch"]
    [2018-01-31 14:47:51.916244492] chat: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","cat-file","--batch-check=%(objectname) %(objecttype) %(objectsize)"]
    [2018-01-31 14:47:51.926062822] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","config","annex.version","5"]
    [2018-01-31 14:47:51.943412825] process done ExitSuccess
    [2018-01-31 14:47:51.943804264] read: git ["config","--null","--list"]
    [2018-01-31 14:47:51.949022318] process done ExitSuccess
    [2018-01-31 14:47:51.952482534] chat: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","hash-object","-w","--stdin-paths","--no-filters"]
    [2018-01-31 14:47:51.954175781] feed: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","update-index","-z","--index-info"]
    [2018-01-31 14:47:51.968113275] process done ExitSuccess
    [2018-01-31 14:47:51.969050491] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","show-ref","--hash","refs/heads/git-annex"]
    [2018-01-31 14:47:51.979633335] process done ExitSuccess
    (recording state in git...)
    [2018-01-31 14:47:51.980277288] read: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","write-tree"]
    [2018-01-31 14:47:51.989727059] process done ExitSuccess
    [2018-01-31 14:47:51.98998106] chat: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","commit-tree","06548fa56acf18f9c1d74a29e248c4650df15e7e","--no-gpg-sign","-p","refs/heads/git-annex"]
    [2018-01-31 14:47:52.011569157] process done ExitSuccess
    [2018-01-31 14:47:52.012198525] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","update-ref","refs/heads/git-annex","26bcec3f33162a9c1c5b7a39c4828eedfdeae41b"]
    [2018-01-31 14:47:52.030929599] process done ExitSuccess
    [2018-01-31 14:47:52.037715315] process done ExitSuccess
    [2018-01-31 14:47:52.038491764] process done ExitSuccess
    [2018-01-31 14:47:52.039098682] process done ExitSuccess
    [2018-01-31 14:47:52.039790346] read: uname ["-n"]
    [2018-01-31 14:47:52.043271433] process done ExitSuccess
    [2018-01-31 14:47:52.043523608] read: git ["config","--null","--list"]
    [2018-01-31 14:47:52.057690629] process done ExitSuccess
    [2018-01-31 14:47:52.058740927] call: git ["--git-dir=../../../../run/media/dxtr/archive/annex","--literal-pathspecs","remote","add","greger","../../../../../home/dxtr/temp/test"]
    [2018-01-31 14:47:52.072184794] process done ExitSuccess
    [2018-01-31 14:47:52.072509479] call: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","-c","core.bare=false","remote","add","archive","/run/media/dxtr/archive/annex"]
    [2018-01-31 14:47:52.081339812] process done ExitSuccess
    [2018-01-31 14:47:52.082154367] read: git ["config","--null","--list"]
    [2018-01-31 14:47:52.093569488] process done ExitSuccess
    31/Jan/2018:14:47:52 +0100 [Error#yesod-core] there is no available git remote named "archive" @(yesod-core-1.4.37-GCI7RasEcSMIU2vku0fHJ1:Yesod.Core.Class.Yesod ./Yesod/Core/Class/Yesod.hs:693:5)

The interesting part here is that if I try to run the failing git commands in the repository it works:

    $ git --git-dir=../../../../run/media/dxtr/archive/annex --literal-pathspecs show-ref git-annex
    26bcec3f33162a9c1c5b7a39c4828eedfdeae41b refs/heads/git-annex


### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)
I have been using it for years. Just not the webapp :)

