hack powerpc64 and solaris

Author: Emilgardis

Dockerfile.hack

@@ -0,0 +1,2 @@
+ARG CROSS_IMAGE
+FROM $CROSS_IMAGE

xtask/src/build_docker_image.rs

@@ -84,7 +84,17 @@ fn locate_dockerfile(
     } else {
         eyre::bail!("unable to find dockerfile for target \"{target}\"");
     };
-    let dockerfile = dockerfile_root.join(dockerfile_name).to_utf8()?.to_string();
+    let dockerfile = if matches!(
+        target.triplet.as_str(),
+        "powerpc64-unknown-linux-gnu" | "x86_64-sun-solaris"
+    ) {
+        crate::util::project_dir(&mut <_>::default())?
+            .join("Dockerfile.hack")
+            .to_utf8()?
+            .to_string()
+    } else {
+        dockerfile_root.join(dockerfile_name).to_utf8()?.to_string()
+    };
     Ok((target, dockerfile))
 }