System.Data.SQLite

When creating sqlite connection on linux I get this exception:

System.DllNotFoundException: SQLite.Interop.dll
  at (wrapper managed-to-native) System.Data.SQLite.UnsafeNativeMethods:sqlite3_config_none (System.Data.SQLite.SQLiteConfigOpsEnum)
  at System.Data.SQLite.SQLite3.StaticIsInitialized () <0x417de370 + 0x00053> in <filename unknown>:0 
  at System.Data.SQLite.SQLiteLog.Initialize () <0x417de070 + 0x0001f> in <filename unknown>:0 
  at System.Data.SQLite.SQLiteConnection..ctor (System.String connectionString, Boolean parseViaFramework) <0x417ce3f0 + 0x000af> in <filename unknown>:0 
  at System.Data.SQLite.SQLiteConnection..ctor (System.String connectionString) <0x417ce3c0 + 0x00013> in <filename unknown>:0 
  at (wrapper remoting-invoke-with-check) System.Data.SQLite.SQLiteConnection:.ctor (string)

UnsafeNativeMethods are indeed hard code bound to SQLite.Interop.dll, but linux doesn't use dlls. How is it supposed to work? PreLoadSQLite_LibraryFileNameOnly doesn't affect it.

Are you using the managed binaries compiled for Mono?

I'm asking because this exact scenario is explicitly tested on both Linux and
Mac OS X.

You can download the precompiled binaries for Mono -OR- you can compile then
using the build scripts included in the source tree.

I use http://system.data.sqlite.org/downloads/1.0.108.0/sqlite-netFx451-binary-Mono-2013-1.0.108.0.zip
I still don't understand, how can this work. It unconditionally loads SQLite.Interop.dll, how can this succeed in theory?

With libSQLite.Interop.so symlink it loads, but system libsqlite doesn't export interop functions. The managed provider won't work with it?

System.EntryPointNotFoundException: sqlite3_prepare_interop
  at (wrapper managed-to-native) System.Data.SQLite.UnsafeNativeMethods:sqlite3_prepare_interop (intptr,intptr,int,intptr&,intptr&,int&)
  at System.Data.SQLite.SQLite3.Prepare (System.Data.SQLite.SQLiteConnection cnn, System.String strSql, System.Data.SQLite.SQLiteStatement previous, UInt32 timeoutMS, System.String& strRemain) <0x41b2e5c0 + 0x0067f> in <filename unknown>:0 
  at System.Data.SQLite.SQLiteCommand.BuildNextCommand () <0x41b2e110 + 0x00239> in <filename unknown>:0

The reason it works is because Mono ends up mapping the DLL name using its
internal algorithm so that "SQLite.Interop.dll" becomes "libSQLite.Interop.so"
(or "libSQLite.Interop.dylib" on Mac OS X).

In fact, during my testing, it would *not* just look for or load the file
"SQLite.Interop.dll" verbatim.

You are correct, System.Data.SQLite is not compiled (on any platform), to be
capable of making use of system installed SQLite core libraries.

It is possible to recompile it in this fashion; however, it is not recommended
nor officially supported.

Looks like interop functions are also missing from amalgamation?

The interop library can be compiled rather simple
gcc -o libSQLite.Interop.so interop.c -shared -lpthread -ldl -DSQLITE_ENABLE_COLUMN_METADATA -fPIC -Os

Would be great to have incompatibility documented, it doesn't look like there are instructions for posix.

Also msil build from nuget works fine. I suppose it's not different from mono build.

The interop assembly build scripts in the source tree do have the appropriate
commands (similar to the one reported above).