Try switching .Decompiler.Console on Release(NuGet)/Debug(ProjectRef). Tested on VS Mac 8.3

Frontends.sln

@@ -14,6 +14,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ICSharpCode.Decompiler.Cons
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ICSharpCode.Decompiler.PowerShell", "ICSharpCode.Decompiler.PowerShell\ICSharpCode.Decompiler.PowerShell.csproj", "{FF7D6041-3C52-47D1-A32A-0BFE8EE4EEEB}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ICSharpCode.Decompiler", "ICSharpCode.Decompiler\ICSharpCode.Decompiler.csproj", "{526B267D-1904-4E9E-80DB-BB2259ADCF6C}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -28,6 +30,10 @@ Global
 		{FF7D6041-3C52-47D1-A32A-0BFE8EE4EEEB}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{FF7D6041-3C52-47D1-A32A-0BFE8EE4EEEB}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{FF7D6041-3C52-47D1-A32A-0BFE8EE4EEEB}.Release|Any CPU.Build.0 = Release|Any CPU
+		{526B267D-1904-4E9E-80DB-BB2259ADCF6C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{526B267D-1904-4E9E-80DB-BB2259ADCF6C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{526B267D-1904-4E9E-80DB-BB2259ADCF6C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{526B267D-1904-4E9E-80DB-BB2259ADCF6C}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

ICSharpCode.Decompiler.Console/ICSharpCode.Decompiler.Console.csproj

@@ -26,9 +26,17 @@
     <WarningsAsErrors>NU1605</WarningsAsErrors>
   </PropertyGroup>
 
+
+  <ItemGroup Condition="'$(Configuration)' == 'Debug'">
+    <ProjectReference Include="..\ICSharpCode.Decompiler\ICSharpCode.Decompiler.csproj" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(Configuration)' == 'Release'">
+    <PackageReference Include="ICSharpCode.Decompiler" Version="5.0.0.5124" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="McMaster.Extensions.CommandLineUtils" Version="2.3.2" />
-    <PackageReference Include="ICSharpCode.Decompiler" Version="5.0.0.5124" />
 
     <PackageReference Include="System.IO.FileSystem.Primitives" Version="4.3.0" />
     <PackageReference Include="System.Runtime.Handles" Version="4.3.0" />