btanalyzer

A .NET CLI tool that analyzes MSBuild binary logs to identify build performance bottlenecks.

It runs dotnet build with binary logging, stream-parses the .binlog, and surfaces the slowest projects and targets with automated diagnostics.

Installation

Download the latest binary for your platform from GitHub Releases and place it on your PATH.

Available binaries: linux-x64, linux-arm64, win-x64, osx-arm64.

Usage

# Analyze the solution in the current directory
btanalyzer build

# Analyze a specific project
btanalyzer build path/to/MyApp.csproj

# Release configuration, show top 10 results
btanalyzer build -c Release -n 10

# Export HTML report
btanalyzer build -o report.html

# Export JSON report
btanalyzer build -o report.json

# Pass extra arguments to dotnet build
btanalyzer build --args "--no-restore"

# Keep the binary log for further inspection
btanalyzer build --keep-log

Options

Option	Short	Default	Description
--configuration	-c	Debug	Build configuration
--top	-n	20	Number of top results to display
--output	-o		Export report to file (.html or .json)
--keep-log			Keep the .binlog file after analysis
--args			Additional arguments passed to dotnet build

What it does

1. Runs dotnet build -bl on your project/solution
2. Stream-parses the binary log (memory-efficient, no full tree loading)
3. Computes exclusive build times by subtracting orchestration task durations (MSBuild/CallTarget)
4. Deduplicates projects by full path and targets by (name, project) pair
5. Runs automated analysis with heuristic-based diagnostics:
   • Bottleneck projects taking a disproportionate share of build time
   • Disproportionately slow projects compared to the next-slowest
   • Project clusters suggesting shared dependency chains
   • Dominant target types (e.g. CoreCompile dominating top targets)
   • Unusually slow individual targets (statistical outliers)
   • Costly package resolution (ResolvePackageAssets > 3s)
   • Warning concentration across projects

Output formats

• Console -- Formatted tables with colored build output
• HTML -- Self-contained dark-themed report with severity coloring
• JSON -- Machine-readable output (AOT-compatible source-generated serialization)

Requirements

Pre-built binaries from GitHub Releases are self-contained and need no runtime.

To build from source: .NET 10 SDK or later.

License

MIT