CHIRP

I cannot get the daily build installed on my Linux Mint. I have used the info in the "Ubuntu Linux Users" on the download page. When I run that in terminal here is what I get:

na4it@na4it-Inspiron-560 ~ $ sudo apt-add-repository ppa:dansmith/chirp-snapshots
[sudo] password for na4it:
You are about to add the following PPA to your system:

More info: https://launchpad.net/~dansmith/+archive/ubuntu/chirp-snapshots
Press [ENTER] to continue or ctrl-c to cancel adding it

Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /tmp/tmp.PhpiCZNiAp --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver hkp://keyserver.ubuntu.com:80/ --recv 837E6991DE70A952C07AE7176EA1BC913BC5163F
gpg: requesting key 3BC5163F from hkp server keyserver.ubuntu.com
gpg: key 3BC5163F: "Launchpad PPA for Dan Smith" not changed
gpg: Total number processed: 1
gpg: unchanged: 1
na4it@na4it-Inspiron-560 ~ $ sudo apt-get update
Get:1 http://security.ubuntu.com precise-security Release.gpg [198 B]

Hit http://packages.linuxmint.com maya Release.gpg

Hit http://archive.canonical.com precise Release.gpg

Hit http://archive.ubuntu.com precise Release.gpg

Get:2 http://archive.ubuntu.com precise-updates Release.gpg [198 B]

Get:3 http://packages.medibuntu.org precise Release.gpg

Get:4 http://ppa.launchpad.net precise Release.gpg [316 B]

Ign http://ppa.launchpad.net maya Release.gpg

Get:5 http://ppa.launchpad.net precise Release.gpg [316 B]

Ign http://ppa.launchpad.net maya Release.gpg

Get:6 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:7 http://ppa.launchpad.net precise Release.gpg [316 B]

Ign http://ppa.launchpad.net maya Release.gpg

Ign http://ppa.launchpad.net maya Release.gpg

Get:8 http://ppa.launchpad.net precise Release.gpg [316 B]

Ign http://ppa.launchpad.net maya Release.gpg

Get:9 http://security.ubuntu.com precise-security Release [55.5 kB]

Hit http://packages.linuxmint.com maya Release

Hit http://archive.canonical.com precise Release

Hit http://archive.ubuntu.com precise Release

Ign http://ppa.launchpad.net maya Release.gpg

Get:10 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:11 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:12 http://ppa.launchpad.net precise Release.gpg [316 B]

Ign http://ppa.launchpad.net maya Release.gpg

Get:13 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:14 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:15 http://ppa.launchpad.net precise Release.gpg [316 B]

Hit http://packages.linuxmint.com maya/main i386 Packages

Get:16 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:17 http://ppa.launchpad.net precise Release.gpg [316 B]

Get:18 http://security.ubuntu.com precise-security/main i386 Packages [710 kB]
Hit http://archive.canonical.com precise/partner i386 Packages

Get:19 http://archive.ubuntu.com precise-updates Release [55.4 kB]

Get:20 http://packages.medibuntu.org precise Release

Get:21 http://ppa.launchpad.net precise Release.gpg [836 B]

Hit http://ppa.launchpad.net precise Release

Ign http://packages.medibuntu.org precise Release

E: GPG error: http://packages.medibuntu.org precise Release: The following signatures were invalid: NODATA 1 NODATA 2
na4it@na4it-Inspiron-560 ~ $ sudo apt-get install chirp-daily
Reading package lists... Done
Building dependency tree

Reading state information... Done
The following packages were automatically installed and are no longer required:
libparams-classify-perl ttf-umefont libxmlrpc-c++4 libmodule-runtime-perl
libdatetime-locale-perl libparams-validate-perl
libdatetime-format-builder-perl libdatetime-format-iso8601-perl
libdatetime-format-strptime-perl libdata-optlist-perl librpc-xml-perl
libclass-factory-util-perl libparams-util-perl winetricks wine-gecko1.4
icoutils libpackage-stash-xs-perl libdatetime-perl libsub-install-perl
libpackage-deprecationmanager-perl libmath-round-perl libpackage-stash-perl
ttf-unfonts-core gnome-exe-thumbnailer libclass-load-perl
libdatetime-timezone-perl libtry-tiny-perl liblist-moreutils-perl
libclass-singleton-perl
Use 'apt-get autoremove' to remove them.
The following packages will be upgraded:
chirp-daily
1 upgraded, 0 newly installed, 0 to remove and 136 not upgraded.
Need to get 627 kB of archives.
After this operation, 239 kB of additional disk space will be used.
Err http://ppa.launchpad.net/dansmith/chirp-snapshots/ubuntu/ precise/main chirp-daily i386 20160923~precise~1
404 Not Found
Failed to fetch http://ppa.launchpad.net/dansmith/chirp-snapshots/ubuntu/pool/main/c/chirp-daily/chirp-daily_20160923~precise~1_i386.deb 404 Not Found
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
na4it@na4it-Inspiron-560 ~ $

What am I doing wrong?