C#, Npgsql and Postgres

Having done some Mono C# today and created a couple of tables in a PostgreSQL database, I thought I would investigate how to access the database from the Mono C#. I found a project that provides a DB connector and I copied the sample C# source code, see the example source.

[greg:~] cd dev/src/csharp
[greg:csharp] mkdir postgres
[greg:csharp] cd postgres
[greg:postgres] git clone git://github.com/franciscojunior/Npgsql2.git
[greg:postgres] cd npgsql2/src
[greg:src] nant
. . . . . 
[greg:src] cd build/ms
[greg:ms] gacutil -i Npgsql.dll
Failure adding assembly Npgsql.dll to the cache: gac directories could not be created, possibly permission issues.
[greg:ms] sudo gacutil -i Npgsql.dll
Password:
Installed Npgsql.dll into the gac (/Library/Frameworks/Mono.framework/Versions/2.10.8/lib/mono/gac)
[greg:ms] cd ~/dev/src/csharp/postgres
[greg:postgres] mcs NpgsqlUserManual.cs -r:System.Data.dll,Npgsql.dll
[greg:postgres] mono NpgsqlUserManual.exe