Directory.Build.targets

<Project>

  <!--
    Package validation — the binary-compatibility gate (#315).

    This lives in Directory.Build.targets rather than Directory.Build.props for
    one reason: IsPackable. Directory.Build.props is imported *before* the
    project body, so at that point every project looks packable. Enabling
    validation there puts a baseline PackageDownload on the test / benchmark /
    fuzz / AOT-smoke projects too, and restore fails with

        error : Invalid framework identifier ''.

    because those projects have no PackageId to resolve a baseline for.
    Directory.Build.targets is imported *after* the project body, so the
    IsPackable=false that each dev project sets is already visible here and the
    shipped packages are the only ones the condition matches.

    The baseline version itself is CelerityPackageValidationBaseline, declared in
    Directory.Build.props — that is the single line to bump at release time, and
    the ritual is documented both there and in CONTRIBUTING.md.

    CelerityNoPublishedBaseline is the escape hatch for a package's *first*
    release: with no published predecessor on NuGet.org, asking for a baseline
    fails the restore. A new package sets the property in its .csproj, ships
    once, then deletes it.
  -->
  <PropertyGroup Condition="'$(IsPackable)' != 'false'">
    <EnablePackageValidation>true</EnablePackageValidation>
    <PackageValidationBaselineVersion Condition="'$(CelerityNoPublishedBaseline)' != 'true'">$(CelerityPackageValidationBaseline)</PackageValidationBaselineVersion>
  </PropertyGroup>

</Project>