libnpgsql-cil-dev 2.2.7+dfsg3-1 (amd64 binary) in ubuntu xenial

 Npgsql is the .NET data provider for PostgreSQL. It allows any
 program developed for .NET framework to access a PostgreSQL
 database server. It is implemented in 100% C# code. PostgreSQL
 versions since 9.0 are officially supported, others may work.
 .
 This package contains development files for Npgsql and will always
 pull in the current default version - and should be used for compilation.