nv - Ninja Build Analyzer and Visualizer

nv is a command-line utility written in Swift that helps analyze Ninja build logs. It parses .ninja_log files to extract build timing information and provides detailed textual output of build durations.

Features

• Log Parsing: Supports Ninja log format version 6
• Build Analysis: Extracts start/end times and durations for each build target
• Sorting: Option to sort output by build duration (longest first)
• Console Output: Displays build targets with their execution times

Usage

Basic Analysis

Analyze a .ninja_log file (defaults to .ninja_log in current directory):

nv

Specify a custom log file:

nv analyze -logfile .ninja_log

Sort by Duration

Sort targets by build time (longest first):

nv -s

Build Statistics

Generate comprehensive build statistics and metrics:

# Detailed statistics summary (default)
nv stats

# Concise build overview
nv stats -f brief

The statistics include:

• Basic metrics: Total/average/median build times, min/max durations
• Statistical analysis: Standard deviation, 95th percentile
• Parallelization analysis: Estimated cores used, parallelization efficiency
• Build efficiency: CPU utilization, wall time vs CPU time
• Performance insights: Fastest/slowest targets, potential bottlenecks
• Dependency analysis: Critical path identification (inferred from timing)