/dotnet:build

Smart build command with fuzzy project/solution matching and optional automatic error fixing via MCP research.

Arguments

Parse arguments from $ARGUMENTS:

Flag	Description	Default
--solution <path>	Target solution (supports fuzzy/partial matching)	Auto-detect
--project <path>	Target project (supports fuzzy/partial matching)	None
--configuration <config>	Build configuration	Debug
--fix	Automatically fix errors using build-fixer agent	false
--verbosity <level>	MSBuild verbosity (q, m, n, d, diag)	minimal
--no-restore	Skip restore step	false

Workflow

Step 1: Locate Target

If --project specified:

1. Use Glob to find matching .csproj files
2. If partial name (e.g., "Api"), match against *Api*.csproj
3. If multiple matches, use AskUserQuestion to clarify
4. If natural language (e.g., "the API project"), use Grep to search project files for context

If --solution specified:

1. Use Glob to find matching .sln files
2. Same fuzzy matching logic as projects

If neither specified:

1. Look for .sln file in current directory or parent directories
2. If multiple solutions found, use AskUserQuestion to select
3. If no solution, look for single .csproj

Step 2: Run Build

Construct and execute build command:

dotnet build "<target>" --configuration <config> --verbosity <verbosity> [--no-restore]

Capture both stdout and stderr for error analysis.

Step 3: Analyze Results

If build succeeds:

• Report success with build time and output location
• List any warnings (grouped by category if many)

If build fails and --fix NOT specified:

• Report errors clearly
• Group errors by type (CS*, MSB*, NU*)
• Suggest running with --fix flag

If build fails and --fix IS specified:

• Parse error codes from output
• Extract relevant context (file, line, error message)
• Spawn build-fixer agent with error context:

Task(dotnet:build-fixer, "Fix the following build errors:

Errors:
<paste parsed errors with file paths and line numbers>

Project/Solution: <target>
Configuration: <config>

Research each error via MCP, apply fixes, and report what was changed.")

Step 4: Retry After Fix (if --fix)

After build-fixer agent completes:

1. Run build again
2. If still errors, retry up to 3 times total
3. Report final status with list of fixes applied

Output Format

Success:

Build succeeded for <target>
  Configuration: <config>
  Time: <duration>
  Output: <path>
  Warnings: <count> (use --verbosity detailed to see)

Failure (no --fix):

Build failed for <target>

Errors (grouped by type):
  CS1061: 3 errors - Member does not exist
  CS0103: 2 errors - Name does not exist in context

Run with --fix to attempt automatic resolution.

Failure (with --fix):

Build failed for <target>

Attempting automatic fix...
  - Fixed CS1061 in Foo.cs:42 (added missing using)
  - Fixed CS0103 in Bar.cs:15 (corrected typo)

Retrying build...
Build succeeded after 2 fix iterations.

Examples

# Build solution in current directory
/dotnet:build

# Build specific project with fuzzy matching
/dotnet:build --project Api

# Build with automatic error fixing
/dotnet:build --fix

# Build Release configuration with detailed output
/dotnet:build --configuration Release --verbosity detailed

# Build specific solution
/dotnet:build --solution MyApp.sln