Question: I am creating SQL Server database (not server) project for our existing database using VS2015 and SSDT (the latest version I think). I ran into a compile error saying :

> 
> Error SQL71501: User: [xxxxx] has an unresolved reference to Login
>  [xxxxxx].
> 
> 
> 

I came across [this](https://social.msdn.microsoft.com/Forums/en-US/1f8226fe-b791-4344-8735-3d38307e8664/error-1-sql03006-user-x-has-an-unresolved-reference-to-login-x?forum=vstsdb) post (the answer by Demetri M), that suggests to create a server project and have a current project reference that, but I do not see an option to create SQL Server SERVER (not Database) project in VS2015.

[This](https://msdn.microsoft.com/en-us/library/84b1se47(v=vs.90).aspx) documentation from MSDN didn't help either.Is this something that is no longer valid?

Answer: 
The Filesystem Hierarchy Standard has a [standard definition for `/etc/os-release`](https://www.freedesktop.org/software/systemd/man/os-release.html), which should be available on most distributions:

> 
> The /etc/os-release and /usr/lib/os-release files contain operating system identification data.
> 
> 
> The basic file format of os-release is a newline-separated list of environment-like shell-compatible variable assignments. It is possible to source the configuration from shell scripts.
> 
> 
> 

This means you can just source `/etc/os-release` and use `$NAME` or `$ID` to identify the distribution. As an example, on Fedora it looks like this:

```
% source /etc/os-release
% echo $NAME
Fedora
% echo $ID
fedora

```

On Debian:

```
% source /etc/os-release
% echo $NAME
Debian GNU/Linux
% echo $ID
debian

```
You could use /etc/issue file for Debian/Ubuntu:

```
root@ubuntu_container:/# cat /etc/issue
Ubuntu 14.04.3 LTS \n \l

```

or /etc/redhat-release for CentOS/Red Hat/Fedora:

```
[root@fedora_container /]# cat /etc/redhat-release 
Fedora release 23 (Twenty Three)

[root@centos_container /]# cat /etc/redhat-release 
CentOS Linux release 7.2.1511 (Core)

```