.Net Build Project.csproj Still Searching Directories

Home Q&A .Net Build Project.csproj Still Searching Directories

Problem Statement

When running the following command to build a single project:

dotnet build project.csproj -c Release

…the .NET SDK unexpectedly searches and builds other .csproj files within the directory tree—even though no explicit project references exist in project.csproj.

Context

File structure:

./project.csproj

./scriptlibrary/Projects/project1/dir1/dir2/project2.csproj

./scriptlibrary/Projects/project1/dir1/dir3/project3.csproj

./scriptlibrary/Projects/project1/dir1/dir4/project4.csproj

Expected Behavior:

Only project.csproj should be built, as it has no project reference to any of the other .csproj files.

Observed Behavior:

All .csproj files are being discovered and built.

Root Cause

When running dotnet build inside a folder that contains a solution file (.sln), the build may behave differently based on project references and global.json settings.

If you run dotnet build inside a directory with multiple project files, the build system might attempt a restore across all discovered .csproj files (depending on SDK version and MSBuild behavior).

If there’s a solution file (*.sln) in the folder, and it references those projects, then dotnet build may implicitly build all projects listed in that solution file—even if a specific .csproj is passed.

Solutions / Workarounds

Option 1: Disable Recursive Search Using –no-dependencies

To restrict the build only to the explicitly passed .csproj file:

dotnet build project.csproj -c Release –no-dependencies

Option 2: Avoid Building Solution File (if exists)

Ensure you’re not accidentally building a .sln file instead of .csproj. Avoid:

dotnet build # Might build the entire solution

Use:

dotnet build ./project.csproj

Option 3: Use MSBuild with Explicit Project

Sometimes MSBuild gives more fine-grained control:

msbuild project.csproj /p:Configuration=Release /p:BuildProjectReferences=false

The /p:BuildProjectReferences=false option prevents MSBuild from following project references (even if defined).

Option 4: Isolate the Project Temporarily

As a fallback:

Temporarily copy the target .csproj file to a clean folder.
Run dotnet build in that isolated directory to ensure no unexpected builds are triggered.