dotnet-skills
Tool MSBuild v0.1.0

Misleading ResolveProjectReferences Time

Guide for interpreting ResolveProjectReferences time in MSBuild performance summaries. Only activate in MSBuild/.NET build context. Activate when ResolveProjectReferences appears as the most expensive target and developers are trying to optimize it directly. Explains that the reported time includes wait time for dependent project builds and is misleading. Guides users to focus on task self-time instead. Do not activate for general build performance -- use build-perf-diagnostics instead.

Workflow

Step 1: Confirm the misleading symptom

Verify that ResolveProjectReferences appears as the top target in the Target Performance Summary. This is the misleading metric.

Step 2: Explain why it is misleading

The reported time includes waiting for dependent projects to build while the MSBuild node is yielded (see dotnet/msbuild#3135). During this wait, the node may be doing useful work on other projects. The target itself does very little work.

Step 3: Redirect to task self-time

Use the Task Performance Summary to identify the real bottleneck.

#### Primary: binlog MCP (preferred)

Use the binlog MCP server expensive_tasks tool to get task self-time rankings directly from the binlog.

#### Fallback: text-log replay (when MCP is unavailable)

dotnet msbuild build.binlog -noconlog -fl "-flp:v=diag;logfile=full.log;performancesummary"
grep "Task Performance Summary" -A 50 full.log

Focus on self-time of actual tasks:

  • Csc: see build-perf-diagnostics skill (Section 2: Roslyn Analyzers)
  • ResolveAssemblyReference: see build-perf-diagnostics skill (Section 1: RAR)
  • Copy: see build-perf-diagnostics skill (Section 4: File I/O)
  • Serialization bottlenecks: see build-parallelism skill

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