微软NuGet包版本号规则咨询：末尾两组数字逻辑解析

Great question! Those trailing numbers in pre-release versions of Microsoft-owned NuGet packages like System.Text.Json are tied to their internal Azure DevOps build pipeline infrastructure. Let me break down exactly what each part means based on the examples you shared:

• 倒数第二组数字（e.g., 20475, 20451, 19551）:
  This is a globally incrementing build ID from Microsoft's internal build system. Every time the team triggers a build for any .NET package (regardless of which major/minor version branch it's from), this ID increases by 1. That's why you see it keep going up even when the major/minor version changes (like moving from 4.x to 5.x). It’s a unique identifier for the specific build run that produced the package, helping engineers trace back to the exact code and configuration used.

• 最后一组数字（e.g., 5, 14, 4）:
  This is the build revision number. If a build with a specific ID fails (due to infrastructure glitches, test failures, or other issues) and the team reruns the same build configuration, this revision number increments. When a new build ID is generated (the previous number goes up), this revision resets to an initial value (it might not always start at 1, depending on pipeline setup).

These internal identifiers aren’t meant to be parsed or interpreted by end-users. Their main purpose is for Microsoft’s engineering teams to debug issues, track builds, and ensure package integrity. As a consumer, you only need to focus on the major/minor version and pre-release label (like rc.2, preview.8) to gauge the package’s maturity and compatibility.

内容的提问来源于stack exchange，提问作者sergi