Troubleshooting build issues

Diagnose environment problems with uno-check

If you're not sure whether your environment is correctly configured for Uno Platform development, running the uno-check command-line tool should be your first step. Find installation instructions and other details here.

Multi-projects structure considerations

Uno uses a multi-project structure, for which each project has to be build individually for errors to disappear from the Error List window (notice the Project column values). In order to clear the Error List window, build the whole solution completely once. Subsequently, build a specific project and prefer the use of the Output tool window (in the menu View -> Output), taking build messages by order of appearance.

Troubleshooting build errors using the build Output Window

To troubleshoot build error, you can change the text output log level:

  • Go to Tools, Options, Projects and Solution, then Build and Run
  • Set MSBuild project build output verbosity to Normal or Detailed
  • Build your project again and take a look at the additional output

Generating MSBuild Binary Log files

If you have trouble building your project, you can get additional information using binary log (binlog) files.

Important: Note that binlog files contain environment variables and csproj files used to build the sources, but not the source files themselves. Make sure to review the content of the file for sensitive information before posting it on a public issue, otherwise contact us on Discord for additional information to send us the build logs.**

From Visual Studio

To use MSBuild binary logs:

  • Go to Tools, Options, Projects and Solution, then Build and Run
  • Set MSBuild project build log verbosity to Detailed or Diagnostics
  • Install the MSBuild log viewer
  • Install the Project System Tools for VS 2022 or VS 2019 add-in
  • Open View > Other Windows > Build Logging, then click the green play button
  • Build your project again and right click the Failed build entry in the Build Logging tool window.
  • The binlog viewer tool will expand to the detailed build error

From the command line

You may be asked to generate a binlog from the command line, as it includes more information (the project structure, but not the source files) that can help troubleshoot issues.

To generate a binlog file from the command line:

  • Open a :

  • Navigate to the folder of the project head

  • For UWP/iOS/Android/macOS projects, type the following:

    msbuild /r /bl MyProject.csproj
  • For other targets (.NET 5+, WebAssembly, Skia, etc...)

    dotnet build /bl MyProject.csproj
  • Once the build has finished, a file named msbuild.binlog is generated next to the .csproj file.