binlog-failure-analysis

# Analyzing MSBuild Failures with Binary Logs Use MSBuild's built-in **binlog replay** to convert binary logs into searchable text logs, then analyze with standard tools (`grep`, `cat`, `head`, `tail`, `find`). ## Build Error Investigation (Primary Workflow) ### Step 1: Replay the binlog to text logs Replay produces multiple focused log files in one pass: ```bash dotnet msbuild build.binlog -noconlog \ -fl -flp:v=diag;logfile=full.log;performancesummary \ -fl1 -flp1:errorsonly;logfile=errors.log \ -fl2 -flp2:warningsonly;logfile=warnings.log ``` > **PowerShell note:** Use `-flp:"v=diag;logfile=full.log;performancesummary"` (quoted semicolons). ### Step 2: Read the errors ```bash cat errors.log ``` This gives all errors with file paths, line numbers, error codes, and project context. ### Step 3: Search for context around specific errors ```bash # Find all occurrences of a specific error code with surrounding context grep -n -B2 -A2 "CS0246" full.log # Find which projects failed to compile grep -i "CoreCompile.*FAILED\|Build FAILED\|error MSB" full.log # Find project build order and results grep "done building project\|Building with" full.log | head -50 ``` ### Step 4: Detect cascading failures Projects that never reached `CoreCompile` failed because a dependency failed, not their own code: ```bash # List all projects that ran CoreCompile grep 'Target "CoreCompile"' full.log | grep -oP 'project "[^"]*"' # Compare against projects that had errors to ident...