Build a "true" single executable in .NET 5.0 for Windows, Linux and MacOs

Have you tried to publish a single executable file in .NET 5.0, and the result was not a single file?

For example, running this command:

dotnet publish My.csproj --configuration Release --framework net5.0 --output publish --self-contained True --runtime win-x64 --verbosity Normal /property:PublishTrimmed=True /property:PublishSingleFile=True

Did your output look something like this? Read further to generate a true single EXE, and it’s easy.

-a---          16/03/2021    23:02         747920 clrcompression.dll
-a---          16/03/2021    23:02        1322384 clrjit.dll
-a---          16/03/2021    23:03        5153168 coreclr.dll
-a---          05/05/2021    16:11       20971736 My.exe
-a---          05/05/2021    16:11          11088 My.pdb
-a---          16/03/2021    23:02        1056632 mscordaccore.dll

What are those files?

• clrcompression.dll: native compression algorithms.
• clrjit.dll: JIT compiler.
• coreclr.dll: runtime.
• mscordaccore.dll: to enable Watson dumps.
• My.pdb: debugging symbols file to allow debugging the code.

Let’s produce a single executable with the above files bundled in. We will skip the production of the PDB file. We added 3 additional parameters in the default command /property:IncludeNativeLibrariesForSelfExtract=True /property:DebugType=None /property:DebugSymbols=False. The end command looks like this:

dotnet publish My.csproj --configuration Release --framework net5.0 --output publish --self-contained True --runtime win-x64 --verbosity Normal /property:PublishTrimmed=True /property:PublishSingleFile=True /property:IncludeNativeLibrariesForSelfExtract=True /property:DebugType=None /property:DebugSymbols=False

And we only have one executable now:

-a---          05/05/2021    16:23       29251959 My.exe

To create a Linux or macOS version of the executable, replace the --runtime parameter. For example --runtime linux-x64 and --runtime osx.11.0-x64 respectively.

A keen eye also notices I was using trimming (/property:PublishTrimmed=True) to remove unused code from the final single executable. If you have trouble publishing your application, try to remove it from the command.

References: .NET Single file design documentation