Problem with case sensitivity (dll vs DLL) on Windows

[alexhudson]

I got this backtrace when running dotnet ef database update on a Core 3.1 app:

---> System.DllNotFoundException: Unable to load DLL 'e_sqlite3' or one of its dependencies: The specified module could not be found. (0x8007007E)
   at System.Runtime.InteropServices.NativeLibrary.LoadByName(String libraryName, QCallAssembly callingAssembly, Boolean hasDllImportSearchPathFlag, UInt32 dllImportSearchPathFlag, Boolean throwOnError)
   at System.Runtime.InteropServices.NativeLibrary.LoadLibraryByName(String libraryName, Assembly assembly, Nullable`1 searchPath, Boolean throwOnError)
   at System.Runtime.InteropServices.NativeLibrary.Load(String libraryName, Assembly assembly, Nullable`1 searchPath)
   at SQLitePCL.NativeLibrary.Load(String libraryName, Assembly assy, Int32 flags)
   at SQLitePCL.Batteries_V2.MakeDynamic(String name, Int32 flags)
   at SQLitePCL.Batteries_V2.DoDynamic_cdecl(String name, Int32 flags)
   at SQLitePCL.Batteries_V2.Init()

From tracing the command, it appears it was looking for C:\Users\username\Projects\projectname\bin\Debug\netcoreapp3.0\runtimes\win-x64\native\e_sqlite3.DLL - which didn't exist, so it was failing.

However, e_sqlite3.dll did exist. I copied it, and uppercased the extension - everything then started working again.

I'm not quite sure how I got it into this state (it was a fresh git checkout, dotnet restore, etc.)!

[kpreisser]

I can reproduce this problem on Windows with .NET Core SDK 3.1.201 when using a case-sensitive directory:

1. Create a new directory and make it case-sensitive (requires Windows 10 Version 1803 or higher, and requires the Windows Subsystem for Linux (WSL) to be enabled in Windows Features):

mkdir "%USERPROFILE%\TestSqlite"
fsutil.exe file setCaseSensitiveInfo "%USERPROFILE%\TestSqlite" enable

2. Create a new .NET Core 3.1 app:

cd "%USERPROFILE%\TestSqlite"
dotnet new console
dotnet add package SQLitePCLRaw.bundle_e_sqlite3 --version 2.0.2

3. Change Program.cs to the following code:

class Program
{
    static void Main()
    {
        SQLitePCL.Batteries_V2.Init();
    }
}

4. Run the program with dotnet run:

C:\Users\developer4\TestSqlite>dotnet run
Unhandled exception. System.DllNotFoundException: Unable to load DLL 'e_sqlite3' or one of its dependencies: The specified module could not be found. (0x8007007E)
   at System.Runtime.InteropServices.NativeLibrary.LoadByName(String libraryName, QCallAssembly callingAssembly, Boolean hasDllImportSearchPathFlag, UInt32 dllImportSearchPathFlag, Boolean throwOnError)
   at System.Runtime.InteropServices.NativeLibrary.LoadLibraryByName(String libraryName, Assembly assembly, Nullable`1 searchPath, Boolean throwOnError)
   at System.Runtime.InteropServices.NativeLibrary.Load(String libraryName, Assembly assembly, Nullable`1 searchPath)
   at SQLitePCL.NativeLibrary.Load(String libraryName, Assembly assy, Int32 flags)
   at SQLitePCL.Batteries_V2.MakeDynamic(String name, Int32 flags)
   at SQLitePCL.Batteries_V2.DoDynamic_cdecl(String name, Int32 flags)
   at SQLitePCL.Batteries_V2.Init()
   at Program.Main() in C:\TestSqlite\Program.cs:line 5

When going into the folder bin\Debug\netcoreapp3.1\runtimes\win-x64\native and renaming e_sqlite3.dll to e_sqlite3.DLL, the exception no longer occurs.

I think the exception can be fixed by specifying the exact file name to NativeLibrary.Load (e_sqlite3.dll rather than e_sqlite3), as apparently LoadLibraryW appends .DLL (rather than .dll) when the file extension is omitted.

Thanks!

[fadamsen]

When using Docker with Windows Subsystem for Linux, this isn't so much an edge-case anymore. The recommendation is to keep files needed for containers in the Linux file system, which is case-sensitive, even though we're still running our IDE (JetBrains Rider in this case) on Windows.

Renaming the file from e_sqlite3.dll to e_sqlite3.DLL does indeed solve the issue, would it be possible to either change the file name or the call to NativeLibrary.Load as suggested above?

[ericsink]

I do agree that I need some kind of a fix here.