Hi- I couldn't install MonetDB on Ubuntu 16.04.1 LTS (Xenial Xerus) hosted on EC2 yesterday.  I kept getting the error below.  It looks like the repository does not have a "source" folder.  However, I noticed that the "Trusty" version had a "source" folder, and so I tried installing the Trusty version on my Xenial box, and it installed successfully.

So far, I haven't encountered any problems, but was there anything I did wrong in the installation process?  Will I encounter problems down the road with the Trusty version installed on a Xenial box?

$ sudo apt-get update
Hit:1 http://us-east-1.ec2.archive.ubuntu.com/ubuntu xenial InRelease
Hit:2 http://us-east-1.ec2.archive.ubuntu.com/ubuntu xenial-updates InRelease
Hit:3 http://us-east-1.ec2.archive.ubuntu.com/ubuntu xenial-backports InRelease
Get:4 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB]
Ign:5 http://dev.monetdb.org/downloads/deb xenial InRelease
Get:6 http://dev.monetdb.org/downloads/deb xenial Release [2,715 B]
Get:7 http://dev.monetdb.org/downloads/deb xenial Release.gpg [163 B]
Fetched 97.3 kB in 0s (185 kB/s)
Reading package lists... Done
W: http://dev.monetdb.org/downloads/deb/dists/xenial/Release.gpg: Signature by key 213E64DCD5DDC2C063CC39FD053C3ED40583366F uses weak digest algorithm (SHA1)
E: Failed to fetch http://dev.monetdb.org/downloads/deb/dists/xenial/Release  Unable to find expected entry 'monetdb/source/Sources' in Release file (Wrong sources.list entry or malformed file)
E: Some index files failed to download. They have been ignored, or old ones used instead.