Default to mold linker

.github/workflows/build.yml

@@ -51,4 +51,4 @@ jobs:
             rust:alpine-mimalloc \
             sh -c 'cargo install names && mv $CARGO_HOME/bin/names .'
           MIMALLOC_VERBOSE=1 ./names
-          ldd ./names
+          file ./names

README.md

@@ -7,5 +7,7 @@ or C/C++ static executables in this image, the resulting executables
 will automatically link with `mimalloc` without needing any special
 build flags.
 
+Supported & tested archs: `amd64` and `arm64v8`.
+
 For more details, see this [blog
 post](https://www.tweag.io/blog/2023-08-10-rust-static-link-with-mimalloc).

build.sh

@@ -11,8 +11,14 @@ apk upgrade --no-cache
 apk add --no-cache \
   alpine-sdk \
   cmake \
+  mold \
   samurai
 
+{
+  echo "[target.$(rustup target list --installed)]"
+  echo 'rustflags = ["-C", "link-arg=-fuse-ld=mold"]'
+} > $CARGO_HOME/config.toml
+
 curl -f -L --retry 5 https://github.com/microsoft/mimalloc/archive/refs/tags/v$MIMALLOC_VERSION.tar.gz | tar xz --strip-components=1
 
 patch -p1 < mimalloc.diff