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
    six 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>