Reproducible builds with Razor Class Library in .NET 6 RC1

[meziantou]

Describe the bug

I try to update a project to .NET 6 RC1. The project is a Razor Class Library that contains Blazor components.
I use the [email protected] package to set the MSBuild properties for reproducible builds. It works great in .NET 5. However, in .NET 6 RC1, the path to the razor files in the pdb are local paths (C:\...) instead of a deterministic path (/_/...).

• .NET 5:

  

• .NET 6:

  

To Reproduce

• Repro - Source code, you can run the CI to generate the NuGet and binlog files or check the following zip files
• binlog + nuget - net5.zip (5.0.401)
• binlog + nuget - net6.zip (6.0.100-rc.1.21458.32)

Is there a new property to set in the csproj file to handle razor files in .NET 6?

[pranavkm]

@meziantou I tried the repro app that you shared, and it looks like the net6.0 app works correctly. I have a rc2 SDK installed:

Are your results different when building locally?

[meziantou]

You can build the .NET 6 project (RazorClassLibrary1) locally using:

dotnet pack /p:GITHUB_ACTIONS=true /bl

/p:GITHUB_ACTIONS=true makes DotNet.ReproducibleBuilds think the project is built on GitHub, so it enables all useful properties (ContinuousIntegrationBuild, source link, etc.)

You can see using NuGet Package Explorer:

• ✔️ Local .cs files are converted to a GitHub link (source link)
• ❌ Razor files have local paths (c:\users\...)
• ✔️Generated files have deterministic paths (/_/...)

Using the .NET SDK 5.0.401

To build the .NET 5 project (RazorClassLibrary2), you may need to use .NET 5 SDK (5.0.401) as the .NET 6 SDK RC1 produces an error because of #35568

You can see using NuGet Package Explorer:

• ✔️ Local .cs files are converted to a GitHub link (source link)
• ✔️ Local .razor files are converted to a GitHub link (source link)
• ✔️Generated files have deterministic paths (/_/...)

dotnet --info

.NET SDK (reflecting any global.json):
 Version:   6.0.100-rc.1.21463.6
 Commit:    e627d556a1

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22000
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\6.0.100-rc.1.21463.6\

Host (useful for support):
  Version: 6.0.0-rc.1.21451.13
  Commit:  d7619cd4b1

.NET SDKs installed:
  5.0.401 [C:\Program Files\dotnet\sdk]
  6.0.100-rc.1.21463.6 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 6.0.0-rc.1.21452.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 6.0.0-rc.1.21451.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 6.0.0-rc.1.21451.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

[pranavkm]

@chsienki / @jaredpar do you know if there's anything we need to do in Razor to address this? Could be that sourcelinks are being correctly resolved for additional files?

[jaredpar]

@clairernovotny, @tmat

Unfortunately the screen shots don't line up with the binlog that are produced here. For example I can't see GeneratedForm.razor in the net6.0 binlog. Maybe I'm doing something subtly wrong here.

[meziantou]

@jaredpar The screenshots from the first post was from another project (before I made the repro projects). The screenshots from the next messages should line up with the binlogs from the first post. Also, you can have a look at the GitHub project which contains the source code for all other screenshots and binlog.

[tmat]

I see the problem.

This is the PathMap that csc receives:

PathMap = 
  C:\Users\runneradmin\.nuget\packages\=/_1/,
  C:\Program Files (x86)\Microsoft Visual Studio\Shared\NuGetPackages\=/_2/,
  C:\Program Files (x86)\Microsoft\Xamarin\NuGet\=/_3/,
  D:\a\repro-reproduciblebuilds\repro-reproduciblebuilds\=/_/,

This is the #line directive that Razor generator emits:

#line "d:\a\repro-reproduciblebuilds\repro-reproduciblebuilds\RazorClassLibrary1\_Imports.razor"

Notice the difference in casing of D drive. This causes mismatch in Source Link map.

The compiler is given the additional paths with lower-case drive, so the source generator is correctly emitting the paths with the given casing.

[pranavkm]

That's sounds like a Razor SDK issue. We were intentionally changing the path root to workaround an issue with O# which was recently resolved. I can take it from here and see if removing the workaround helps.

[pranavkm]

@meziantou this was resolved as part of dotnet/sdk#21806. A nightly build from the Release/6.0.1XX channel - https://github.com/dotnet/installer#installers-and-binaries - should have this fix if you'd like to give this a try.

[meziantou]

Thanks @pranavkm! I gave it a try this morning and it's all green using 6.0.100-rtm.21508.2 😊
Do you know if the fix will be part of RC2 (it is not in the daily build), or do I have to wait for the RTM in November?

[pranavkm]

Do you know if the fix will be part of RC2

RC2 builds are mostly wrapped up now, the fix targets RTM.