Rust compiler can generate a single binary that contains all dependencies. This is a great feature for creating stand-alone tools or tools for containers.
There is one gotcha for Windows which does not appear on a developer’s machine. When you move the application to a brand new installation of Windows or you try to start the in Windows Docker Container which contains Windows for Datacenters the app won’t start.
Why? The system is missing Microsoft Visual C++ Redistributable 2015-2019 (vc_redist) which you can download from microsoft.com.
It’s quite inconvenient to force the user to install the package in the case of a stand-alone Rust tool. The package installation even requires elevation of privileges.
The alternative approach to distributing vc_redist is to statically link CRT library into the application. It will result in a slightly bigger application around +100KB.
It’s necessary to tell rustc to perform static linking of CRT.
In the project create file .cargo/config.toml:
[target.x86_64-pc-windows-msvc] rustflags = ["-C", "target-feature=+crt-static"]
Rebuild the application and the new binary is statically linked and can run even on Windows 8 without vc_redist.
The interesting part is how to determine the proper target name which is on the first line of the example configuration. Many examples on the internet are referring to target.i686-pc-windows-msvc which does not work. Use the following command to determine parts of the name of the target:
rustc --print cfg target_arch="x86_64" target_endian="little" target_env="msvc" target_family="windows" target_feature="fxsr" target_feature="sse" target_feature="sse2" target_os="windows" target_pointer_width="64" target_vendor="pc" windows
The target name is composed of values on the lines above.