$basearch parameter in repo url is not being resolved

I've tested and it worked properly. If should be fixed in Feb with #8 (see listing below).

Maybe your package is outdated somehow? Or somehow file /etc/proc/sys/kernel/arch is missing, because sypper reads $arch from there (and $basearch is assigned from $arch by default).

> sudo zypper ar -f -c 'https://packagecloud.io/slacktechnologies/slack/fedora/21/$basearch' test
[sudo] password for root: 
Adding repository 'test' .................................................[done]
Repository 'test' successfully added

URI         : https://packagecloud.io/slacktechnologies/slack/fedora/21/x86_64
Enabled     : Yes
GPG Check   : Yes
Autorefresh : Yes
Priority    : 99 (default priority)

Repository priorities in effect:                (See 'zypper lr -P' for details)
      90 (raised priority)  :  1 repository
      99 (default priority) : 20 repositories
> 
> 
> 
> sudo zypper -vvv ref -f test
Verbosity: 3
Non-option programme arguments: 'test' 
Initialising Target
Specified repositories: test 
Forcing raw metadata refresh
Retrieving: https://packagecloud.io/slacktechnologies/slack/fedora/21/x86_64/repodata/repomd.xml.asc .........................................................................................................................................[done (833 B/s)]
Retrieving: https://packagecloud.io/slacktechnologies/slack/fedora/21/x86_64/repodata/repomd.xml.key .......................................................................................................................................[done (3.9 KiB/s)]
Retrieving: https://packagecloud.io/slacktechnologies/slack/fedora/21/x86_64/repodata/repomd.xml ...........................................................................................................................................[done (1.8 KiB/s)]
  Repository:       test
  Key Fingerprint:  DB08 5A08 CA13 B8AC B917 E0F6 D938 EC0D 0386 51BD
  Key Name:         https://packagecloud.io/slacktechnologies/slack (https://packagecloud.io/docs#gpg_signing) <support@packagecloud.io>
  Key Algorithm:    RSA 4096
  Key Created:      Thu 18 Feb 2016 18:46:55 CET
  Key Expires:      (does not expire)
  Subkey:           C6ABDCF64DB9A0B2 2016-02-18 [does not expire]
  Rpm Name:         gpg-pubkey-038651bd-56c6038f
Retrieving: https://packagecloud.io/slacktechnologies/slack/fedora/21/x86_64/repodata/4e2cf7a05b7324e5df59ea89f52d84632797d355-primary.xml.gz ..............................................................................................[done (2.4 KiB/s)]
Retrieving repository 'test' metadata ..................................................................................................................................................................................................................[done]
Forcing building of repository cache
Building repository 'test' cache .......................................................................................................................................................................................................................[done]
Specified repositories have been refreshed.
> 
> 
> grep baseurl /etc/zypp/repos.d/test.repo 
baseurl=https://packagecloud.io/slacktechnologies/slack/fedora/21/$basearch

andrii-suse / sypper

$basearch parameter in repo url is not being resolved #15