4 files changed, 11 insertions, 74 deletions
diff --git a/src/SMAPI.ModBuildConfig/BuildTasks/ValidateInstallTask.cs b/src/SMAPI.ModBuildConfig/BuildTasks/ValidateInstallTask.cs
deleted file mode 100644
index 2cc7dc9c..00000000
--- a/src/SMAPI.ModBuildConfig/BuildTasks/ValidateInstallTask.cs
+++ /dev/null
@@ -1,70 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using Microsoft.Build.Framework;
-using Microsoft.Build.Utilities;
-using StardewModdingAPI.ModBuildConfig.Framework;
-
-namespace StardewModdingAPI.ModBuildConfig.BuildTasks
-{
-    /// <summary>A build task which validates the install context.</summary>
-    public class ValidateInstallTask : Task
-    {
-        /*********
-        ** Properties
-        *********/
-        /// <summary>The MSBuild platforms recognised by the build configuration.</summary>
-        private readonly HashSet<string> ValidPlatforms = new HashSet<string>(new[] { "OSX", "Unix", "Windows_NT" }, StringComparer.InvariantCultureIgnoreCase);
-
-        /// <summary>The name of the game's main executable file.</summary>
-        private string GameExeName => this.Platform == "Windows_NT"
-            ? "Stardew Valley.exe"
-            : "StardewValley.exe";
-
-        /// <summary>The name of SMAPI's main executable file.</summary>
-        private readonly string SmapiExeName = "StardewModdingAPI.exe";
-
-
-        /*********
-        ** Accessors
-        *********/
-        /// <summary>The folder containing the game files.</summary>
-        public string GameDir { get; set; }
-
-        /// <summary>The MSBuild OS value.</summary>
-        public string Platform { get; set; }
-
-
-        /*********
-        ** Public methods
-        *********/
-        /// <summary>When overridden in a derived class, executes the task.</summary>
-        /// <returns>true if the task successfully executed; otherwise, false.</returns>
-        public override bool Execute()
-        {
-            try
-            {
-                if (!this.ValidPlatforms.Contains(this.Platform))
-                    throw new UserErrorException($"The mod build package doesn't recognise OS type '{this.Platform}'.");
-                if (!Directory.Exists(this.GameDir))
-                    throw new UserErrorException("The mod build package can't find your game path. See https://github.com/Pathoschild/SMAPI/blob/develop/docs/mod-build-config.md for help specifying it.");
-                if (!File.Exists(Path.Combine(this.GameDir, this.GameExeName)))
-                    throw new UserErrorException($"The mod build package found a game folder at {this.GameDir}, but it doesn't contain the {this.GameExeName} file. If this folder is invalid, delete it and the package will autodetect another game install path.");
-                if (!File.Exists(Path.Combine(this.GameDir, this.SmapiExeName)))
-                    throw new UserErrorException($"The mod build package found a game folder at {this.GameDir}, but it doesn't contain SMAPI. You need to install SMAPI before building the mod.");
-
-                return true;
-            }
-            catch (UserErrorException ex)
-            {
-                this.Log.LogErrorFromException(ex);
-                return false;
-            }
-            catch (Exception ex)
-            {
-                this.Log.LogError($"The mod build package failed trying to deploy the mod.\n{ex}");
-                return false;
-            }
-        }
-    }
-}
diff --git a/src/SMAPI.ModBuildConfig/BuildTasks/DeployModTask.cs b/src/SMAPI.ModBuildConfig/DeployModTask.cs
index 433e602f..a09dd5d2 100644
--- a/src/SMAPI.ModBuildConfig/BuildTasks/DeployModTask.cs
+++ b/src/SMAPI.ModBuildConfig/DeployModTask.cs
@@ -6,7 +6,7 @@ using Microsoft.Build.Framework;
 using Microsoft.Build.Utilities;
 using StardewModdingAPI.ModBuildConfig.Framework;
 
-namespace StardewModdingAPI.ModBuildConfig.BuildTasks
+namespace StardewModdingAPI.ModBuildConfig
 {
     /// <summary>A build task which deploys the mod files and prepares a release zip.</summary>
     public class DeployModTask : Task
diff --git a/src/SMAPI.ModBuildConfig/StardewModdingAPI.ModBuildConfig.csproj b/src/SMAPI.ModBuildConfig/StardewModdingAPI.ModBuildConfig.csproj
index 0007e53e..e04f09a7 100644
--- a/src/SMAPI.ModBuildConfig/StardewModdingAPI.ModBuildConfig.csproj
+++ b/src/SMAPI.ModBuildConfig/StardewModdingAPI.ModBuildConfig.csproj
@@ -38,8 +38,7 @@
     <Reference Include="System.Web.Extensions" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="BuildTasks\ValidateInstallTask.cs" />
-    <Compile Include="BuildTasks\DeployModTask.cs" />
+    <Compile Include="DeployModTask.cs" />
     <Compile Include="Framework\UserErrorException.cs" />
     <Compile Include="Framework\ModFileManager.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
diff --git a/src/SMAPI.ModBuildConfig/build/smapi.targets b/src/SMAPI.ModBuildConfig/build/smapi.targets
index 9f3f13f5..f7e75e23 100644
--- a/src/SMAPI.ModBuildConfig/build/smapi.targets
+++ b/src/SMAPI.ModBuildConfig/build/smapi.targets
@@ -118,9 +118,17 @@
   <!--*********************************************
   ** Deploy mod files & create release zip after build
   **********************************************-->
+  <!-- if game path or OS is invalid, show one user-friendly error instead of a slew of reference errors -->
   <Target Name="BeforeBuild">
-    <ValidateInstallTask GameDir="$(GamePath)" Platform="$(OS)" />
+    <Error Condition="'$(OS)' != 'OSX' AND '$(OS)' != 'Unix' AND '$(OS)' != 'Windows_NT'" Text="The mod build package doesn't recognise OS type '$(OS)'." />
+
+    <Error Condition="!Exists('$(GamePath)')" Text="The mod build package can't find your game folder. You can specify where to find it; see details at https://github.com/Pathoschild/SMAPI/blob/develop/docs/mod-build-config.md#game-path." />
+    <Error Condition="'$(OS)' == 'Windows_NT' AND !Exists('$(GamePath)\Stardew Valley.exe')" Text="The mod build package found a a game folder at $(GamePath), but it doesn't contain the Stardew Valley.exe file. If this folder is invalid, delete it and the package will autodetect another game install path." />
+    <Error Condition="'$(OS)' != 'Windows_NT' AND !Exists('$(GamePath)\StardewValley.exe')" Text="The mod build package found a a game folder at $(GamePath), but it doesn't contain the StardewValley.exe file. If this folder is invalid, delete it and the package will autodetect another game install path." />
+    <Error Condition="!Exists('$(GamePath)\StardewModdingAPI.exe')" Text="The mod build package found a game folder at $(GamePath), but it doesn't contain SMAPI. You need to install SMAPI before building the mod." />
   </Target>
+
+  <!-- deploy mod files & create release zip -->
   <Target Name="AfterBuild">
     <DeployModTask
       ModFolderName="$(ModFolderName)"