dotnet-ef fails to retrieve metadata for UNC project paths containing spaces

[MircoGnz]

Bug description

dotnet-ef fails during project metadata retrieval when --project and --startup-project point to an SDK-style project through a UNC path containing spaces.

The verbose output shows that the original project path begins with the normal UNC prefix (\\FILESERVER\...), but the generated dotnet msbuild invocation receives a path with four leading backslashes inside the quoted argument (\\\\FILESERVER\...).

The same project can be processed by mapping the UNC share to a drive letter first.

Your code

The affected project is an SDK-style .NET project targeting `net10.0`.

The issue can be reproduced with this command:


dotnet tool run dotnet-ef migrations list `
  --project "\\FILESERVER\DevShare\Sample Solution\Server\Api Project\Api Project.csproj" `
  --startup-project "\\FILESERVER\DevShare\Sample Solution\Server\Api Project\Api Project.csproj" `
  --context SampleDbContext `
  --framework net10.0 `
  --verbose


Anonymized project path:


\\FILESERVER\DevShare\Sample Solution\Server\Api Project\Api Project.csproj


The EF Core CLI is installed as a local tool and invoked through:


dotnet tool run dotnet-ef

Stack traces

Microsoft.EntityFrameworkCore.Tools.CommandException: Unable to retrieve project metadata. Ensure it's an SDK-style project.
   at Microsoft.EntityFrameworkCore.Tools.Project.FromFile(String file, String framework, String configuration, String runtime)
   at Microsoft.EntityFrameworkCore.Tools.RootCommand.Execute(String[] _)
   at Microsoft.EntityFrameworkCore.Tools.Commands.CommandBase.<>c__DisplayClass0_0.<Configure>b__0(String[] args)
   at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args)
   at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)

Verbose output

Using project '\\FILESERVER\DevShare\Sample Solution\Server\Api Project\Api Project.csproj'.
Using startup project '\\FILESERVER\DevShare\Sample Solution\Server\Api Project\Api Project.csproj'.
dotnet msbuild /property:TargetFramework=net10.0 /getProperty:ProjectName /getProperty:AssemblyName /getProperty:DesignAssembly /getProperty:Language /getProperty:OutputPath /getProperty:PlatformTarget /getProperty:ProjectAssetsFile /getProperty:ProjectDir /getProperty:RootNamespace /getProperty:RuntimeFrameworkVersion /getProperty:TargetFileName /getProperty:TargetFrameworkMoniker /getProperty:Nullable /getProperty:TargetFramework /getProperty:TargetPlatformIdentifier /getProperty:Platform /t:ResolvePackageAssets /getItem:RuntimeCopyLocalItems "\\\\FILESERVER\DevShare\Sample Solution\Server\Api Project\Api Project.csproj"
Microsoft.EntityFrameworkCore.Tools.CommandException: Unable to retrieve project metadata. Ensure it's an SDK-style project.
   at Microsoft.EntityFrameworkCore.Tools.Project.FromFile(String file, String framework, String configuration, String runtime)
   at Microsoft.EntityFrameworkCore.Tools.RootCommand.Execute(String[] _)
   at Microsoft.EntityFrameworkCore.Tools.Commands.CommandBase.<>c__DisplayClass0_0.<Configure>b__0(String[] args)
   at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args)
   at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)
Unable to retrieve project metadata. Ensure it's an SDK-style project.

EF Core version

10.0.7

Database provider

Microsoft.EntityFrameworkCore.SqlServer

Target framework

.NET 10.0

Operating system

Windows 11

IDE

Not applicable — reproduced using dotnet CLI / dotnet-ef local tool