Change chapters 1-5 to treat warnings as errors
MODIFY
src/Chapter04/Chapter04.csproj
src/Chapter04/Chapter04.csproj
<StartupObject>AddisonWesley.Michaelis.EssentialCSharp.Shared.Program</StartupObject>
<Nullable>enable</Nullable>
<LangVersion>8.0</LangVersion>
+ <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+ <WarningsAsErrors />
+ <WarningsNotAsErrors>1030</WarningsNotAsErrors>
+ </PropertyGroup>
+ <PropertyGroup Condition="'$(IgnoreExpectedWarnings)'=='true'">
+ <NoWarn>1030</NoWarn>
</PropertyGroup>
<Import Project="..\Versioning.targets" />
<ItemGroup>

MODIFY
src/Chapter05/Chapter05.csproj
src/Chapter05/Chapter05.csproj
<StartupObject>AddisonWesley.Michaelis.EssentialCSharp.Shared.Program</StartupObject>
<Nullable>enable</Nullable>
<LangVersion>8.0</LangVersion>
+ <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+ <WarningsAsErrors />
</PropertyGroup>
<Import Project="..\Versioning.targets" />
<ItemGroup>

Change chapters 1-5 to treat warnings as errors