make doc-builder example faster

Author: syphar

Diff for: examples/docs-builder.rs

@@ -1,3 +1,4 @@
+use rustwide::cmd::SandboxImage;
 use rustwide::{cmd::SandboxBuilder, Crate, Toolchain, WorkspaceBuilder};
 use std::error::Error;
 use std::path::Path;
@@ -7,7 +8,11 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     // Create a new workspace in .workspaces/docs-builder
     let workspace =
-        WorkspaceBuilder::new(Path::new(".workspaces/docs-builder"), "rustwide-examples").init()?;
+        WorkspaceBuilder::new(Path::new(".workspaces/docs-builder"), "rustwide-examples")
+            .sandbox_image(SandboxImage::remote(
+                "ghcr.io/rust-lang/crates-build-env/linux-micro",
+            )?)
+            .init()?;
 
     // Run the builds on stable
     let toolchain = Toolchain::dist("stable");