dnf install throws errors

I'm not sure what exactly they mean, but I got 2 errors when installing RPM on Fedora 23:

[root@fullmoon ~]# dnf install https://prerelease.keybase.io/keybase_amd64.rpm
Last metadata expiration check: 0:47:46 ago on Wed Sep 21 03:10:40 2016.
Dependencies resolved.
==============================================================================================================================================================
 Package                       Arch                         Version                                                  Repository                          Size
==============================================================================================================================================================
Installing:
 keybase                       x86_64                       1.0.17.20160920160056.1e8543e-1                          @commandline                        56 M

Transaction Summary
==============================================================================================================================================================
Install  1 Package

Total size: 56 M
Installed size: 161 M
Is this ok [y/N]: y
Downloading Packages:
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Installing  : keybase-1.0.17.20160920160056.1e8543e-1.x86_64                                                                                            1/1 
error: can't create transaction lock on /var/lib/rpm/.rpm.lock (Resource temporarily unavailable)
error: /tmp/keybase.sig.mwxLya: key 1 import failed.
Redirecting to /bin/systemctl start  atd.service
  Verifying   : keybase-1.0.17.20160920160056.1e8543e-1.x86_64                                                                                            1/1 

Installed:
  keybase.x86_64 1.0.17.20160920160056.1e8543e-1                                                                                                              

Complete!
[root@fullmoon ~]# cat /etc/yum.repos.d/keybase.repo 
[keybase]
name=keybase
baseurl=http://prerelease.keybase.io/rpm/x86_64
enabled=1
gpgcheck=1
gpgkey=https://keybase.io/docs/server_security/code_signing_key.asc
[root@fullmoon ~]# 

I just started playing a bit wirh keybase; all seems to work fine.

Start by reproducing the reported dnf install https://prerelease.keybase.io/keybase_amd64.rpm command on Fedora 23 and capture the transaction output. Investigate the transaction-lock and key-import errors shown in the report, then confirm the package installs without those errors while preserving the reported successful installation behavior.