twoliter: Use unique token for sdk container

twoliter/src/cmd/build.rs

@@ -41,14 +41,15 @@ pub(crate) struct BuildVariant {
 impl BuildVariant {
     pub(super) async fn run(&self) -> Result<()> {
         let project = project::load_or_find_project(self.project_path.clone()).await?;
+        let token = project.token();
         let tempdir = tools_tempdir()?;
         install_tools(&tempdir).await?;
         let makefile_path = tempdir.path().join("Makefile.toml");
         let packages_dir =
             TempDir::new().context("Unable to create a tempdir for Twoliter's packages")?;
 
         let sdk_container = DockerContainer::new(
-            "sdk",
+            format!("sdk-{}", token),
             project
                 .sdk(&self.arch)
                 .context("The project was missing an sdk")?

twoliter/src/project.rs

@@ -5,6 +5,7 @@ use log::{debug, trace};
 use non_empty_string::NonEmptyString;
 use serde::de::Error;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use sha2::{Digest, Sha512};
 use std::fmt;
 use std::path::{Path, PathBuf};
 use tokio::fs;
@@ -115,6 +116,13 @@ impl Project {
     pub(crate) fn toolchain(&self, arch: &str) -> Option<ImageArchUri> {
         self.toolchain_name().map(|s| s.uri(arch))
     }
+
+    pub(crate) fn token(&self) -> String {
+        let mut d = Sha512::new();
+        d.update(self.filepath().display().to_string());
+        let digest = hex::encode(d.finalize());
+        (digest[..12]).to_string()
+    }
 }
 
 /// A base name for an image that can be suffixed using a naming convention. For example,