Analyze MSBuild binary logs to diagnose build failures. USE FOR: build errors that are unclear from console output, diagnosing cascading failures across multi-project builds, tracing MSBuild target execution order, and generally any MSBuild build issues. Requires an existing .binlog file. DO NOT USE FOR: generating binlogs (use binlog-generation), non-MSBuild build systems.
NewMaintained
Automatic
◆Coding pack
Last verified 8/11/2026
What it changes
Passed 8 of 19 test cases with the skill, and 11 of 19 without it.
Without skill60%
With skill40%
Checks it passed that the model alone missed
Includes `-noconlog` in the MSBuild replay command line.
Includes `-flp:v=diag` to configure diagnostic verbosity for the primary file logger.
Includes `/bl:build.binlog` or `/binaryLogger:build.binlog` switch in the `dotnet build` invocation.
and 2 more in the full report
4 fixed10 passed either way5 still failing3 broke
Pass-rate lift
-20 pp
Tokens
-1%
Agent turns
0%
Response time
-42%
Model gemini-3.6-flashMeasured 8/11/2026v214 of 22 cases passed with skill · 19 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 4 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 4
Prompt
I need to capture a fresh binary log from a failing build of my solution because I don't have one yet. What exact command creates a file named `build.binlog`?
What was checked, without and with the skill
Checked
Without skill
With skill
Includes `/bl:build.binlog` or `/binaryLogger:build.binlog` switch in the `dotnet build` invocation.
Missed
Passed
case-09 · gemini-3.6-flash · 8/11/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md57 linessingle file
Analyzing MSBuild Failures with Binary Logs
This skill diagnoses MSBuild build failures from a .binlog file. The preferred
path uses the binlog MCP server (Microsoft.AITools.BinlogMcp, exposed under the
binlog MCP namespace) which is bundled with this plugin. If the MCP server is
not available, fall back to the binlog replay workflow at the bottom.
Primary workflow — binlog MCP
The MCP server exposes structured tools for inspecting a .binlog without
parsing text logs. Call them directly instead of replaying the binlog to a text
file. Call tools/list for the MCP first if you are unsure which tools are available.
Important constraints:
The .binlog file is a binary format — do NOT try to cat, head, strings, or read it directly. Use only the MCP tools to query it.
The original source/project files might or might NOT be available on disk. Project files (.csproj, .props, .targets, App.config, etc.) - if you cannot locate them on disk, they can only be read from within the binlog via MCP tools (e.g., embedded/source file retrieval).
Synthesize findings as you go. Do not spend all available time investigating — once you have enough evidence, present your conclusions. A partial answer with clear reasoning is better than timing out mid-investigation.
Use the available MCP server tools to query the binary log for: