How to detect the status of msbuild from command line or C# Application

Question

I am writing up a checkout, build and deployment application in C#, and need to know the best way to detect whether my call to msbuild.exe has succeeded or not.

Answer 1

Sorry if I'm a little bit too late for the party... but nearly 7 years after the question was posted I wanted to see a complete answer for it. I did some tests using the code below, and here are the conclusions:

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Analysis

msbuild.exe returns 1 when at least one build error occurs, and returns 0 when the build is successfully completed. At present, the program does not take warnings into account, which means a successful build with warnings causes msbuild.exe to still return 0.

Other errors like: trying to build a project that does not exist, or providing an incorrect argument (like /myInvalidArgument), will also cause msbuild.exe to return 1.

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Source Code

The following C# code is a complete implementation for building your favorite projects by firing msbuild.exe from a command line. Don't forget to setup any necessary environment settings before compiling your projects.

Your BuildControl class:

using System;

namespace Example
{
    public sealed class BuildControl
    {
        // ...

        public bool BuildStuff()
        {
            MsBuilder builder = new MsBuilder(@"C:\...\project.csproj", "Release", "x86")
            {
                Target = "Rebuild", // for rebuilding instead of just building
            };
            bool success = builder.Build(out string buildOutput);
            Console.WriteLine(buildOutput);
            return success;
        }

        // ...
    }
}

MsBuilder class: Builds stuff by calling MsBuild.exe from command line:

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace Example
{
    public sealed class MsBuilder
    {
        public string ProjectPath { get; }
        public string LogPath { get; set; }

        public string Configuration { get; }
        public string Platform { get; }

        public int MaxCpuCount { get; set; } = 1;
        public string Target { get; set; } = "Build";

        public string MsBuildPath { get; set; } =
            @"C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\MsBuild.exe";

        public string BuildOutput { get; private set; }

        public MsBuilder(string projectPath, string configuration, string platform)
        {
            ProjectPath = !string.IsNullOrWhiteSpace(projectPath) ? projectPath : throw new ArgumentNullException(nameof(projectPath));
            if (!File.Exists(ProjectPath)) throw new FileNotFoundException(projectPath);
            Configuration = !string.IsNullOrWhiteSpace(configuration) ? configuration : throw new ArgumentNullException(nameof(configuration));
            Platform = !string.IsNullOrWhiteSpace(platform) ? platform : throw new ArgumentNullException(nameof(platform));
            LogPath = Path.Combine(Path.GetDirectoryName(ProjectPath), $"{Path.GetFileName(ProjectPath)}.{Configuration}-{Platform}.msbuild.log");
        }

        public bool Build(out string buildOutput)
        {
            List arguments = new List()
            {
                $"/nologo",
                $"\"{ProjectPath}\"",
                $"/p:Configuration={Configuration}",
                $"/p:Platform={Platform}",
                $"/t:{Target}",
                $"/maxcpucount:{(MaxCpuCount > 0 ? MaxCpuCount : 1)}",
                $"/fileLoggerParameters:LogFile=\"{LogPath}\";Append;Verbosity=diagnostic;Encoding=UTF-8",
            };

            using (CommandLineProcess cmd = new CommandLineProcess(MsBuildPath, string.Join(" ", arguments)))
            {
                StringBuilder sb = new StringBuilder();
                sb.AppendLine($"Build started: Project: '{ProjectPath}', Configuration: {Configuration}, Platform: {Platform}");

                // Call MsBuild:
                int exitCode = cmd.Run(out string processOutput, out string processError);

                // Check result:
                sb.AppendLine(processOutput);
                if (exitCode == 0)
                {
                    sb.AppendLine("Build completed successfully!");
                    buildOutput = sb.ToString();
                    return true;
                }
                else
                {
                    if (!string.IsNullOrWhiteSpace(processError))
                        sb.AppendLine($"MSBUILD PROCESS ERROR: {processError}");
                    sb.AppendLine("Build failed!");
                    buildOutput = sb.ToString();
                    return false;
                }
            }
        }

    }
}

CommandLineProcess class - Starts a command line process and waits until it finishes. All standard output/error is captured, and no separate window is started for the process:

using System;
using System.Diagnostics;
using System.IO;

namespace Example
{
    public sealed class CommandLineProcess : IDisposable
    {
        public string Path { get; }
        public string Arguments { get; }
        public bool IsRunning { get; private set; }
        public int? ExitCode { get; private set; }

        private Process Process;
        private readonly object Locker = new object();

        public CommandLineProcess(string path, string arguments)
        {
            Path = path ?? throw new ArgumentNullException(nameof(path));
            if (!File.Exists(path)) throw new ArgumentException($"Executable not found: {path}");
            Arguments = arguments;
        }

        public int Run(out string output, out string err)
        {
            lock (Locker)
            {
                if (IsRunning) throw new Exception("The process is already running");

                Process = new Process()
                {
                    EnableRaisingEvents = true,
                    StartInfo = new ProcessStartInfo()
                    {
                        FileName = Path,
                        Arguments = Arguments,
                        UseShellExecute = false,
                        RedirectStandardOutput = true,
                        RedirectStandardError = true,
                        CreateNoWindow = true,
                    },
                };

                if (!Process.Start()) throw new Exception("Process could not be started");
                output = Process.StandardOutput.ReadToEnd();
                err = Process.StandardError.ReadToEnd();
                Process.WaitForExit();
                try { Process.Refresh(); } catch { }
                return (ExitCode = Process.ExitCode).Value;
            }
        }

        public void Kill()
        {
            lock (Locker)
            {
                try { Process?.Kill(); }
                catch { }
                IsRunning = false;
                Process = null;
            }
        }

        public void Dispose()
        {
            try { Process?.Dispose(); }
            catch { }
        }
    }
}

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PS: I'm using Visual Studio 2017 / .NET 4.7.2