Can mill native launcher be statically linked?

[jackkoenig]

In the hardware industry, it's common to have an older Linux distro, e.g. RHEL8 is really common which will gives the following linkage error when trying out Mill 1.0.0.

/scratch/koenig/.cache/mill/download/1.0.0-native-linux-amd64: /lib64/libc.so.6: version `GLIBC_2.32' not found (required by /scratch/koenig/.cache/mill/download/1.0.0-native-linux-amd64)
/scratch/koenig/.cache/mill/download/1.0.0-native-linux-amd64: /lib64/libc.so.6: version `GLIBC_2.34' not found (required by /scratch/koenig/.cache/mill/download/1.0.0-native-linux-amd64)

This can be worked around by using the JVM version of the client, but it would be nice if the client could be statically linked.

[lihaoyi]

Mill delegates the native image building to Graal. Perhaps you could try following https://www.graalvm.org/latest/reference-manual/native-image/guides/build-static-executables/ and adding --static-nolibc in dist/package.mill's nativeImageOptions, running ./mill show dist.native.executable to generate a statically linked executable? If it works, we could make it the default, or available with a version suffix like -static

[lihaoyi]

Building a native executable with --static-nolibc seems to work

$ git diff
diff --git a/dist/package.mill b/dist/package.mill
index fc069e6357c..5012e87e684 100644
--- a/dist/package.mill
+++ b/dist/package.mill
@@ -306,7 +306,8 @@ object `package` extends MillJavaModule with DistModule {
     def nativeImageOptions = Seq(
       "--no-fallback",
       "--enable-url-protocols=https",
-      "-Os"
+      "-Os",
+      "--static-nolibc"
       // Enable JVisualVM support
       // https://www.graalvm.org/latest/tools/visualvm/#using-visualvm-with-graalvm-native-executables
       // "--enable-monitoring=jvmstat,heapdump"

@jackkoenig probably need you to try it out and see if it fixes the problem in your environment, if it does then we can just turn it on by default