Run nix build.

src/config/root.rs

@@ -15,7 +15,7 @@ use super::TargetConfig;
 pub(crate) struct Config {
     #[serde(skip)]
     config_path: Option<PathBuf>,
-    work_directory: Option<PathBuf>,
+    output_directory: Option<PathBuf>,
     targets: Vec<TargetConfig>,
 }
 
@@ -63,9 +63,9 @@ impl Config {
         Ok(target_config)
     }
 
-    pub(crate) fn get_work_directory(&self) -> Result<Cow<'_, Path>, CustomError> {
-        let maybe_work_directory = self.work_directory.as_deref().map(Cow::Borrowed);
-        if let Some(work_dir) = maybe_work_directory {
+    pub(crate) fn get_output_directory(&self) -> Result<Cow<'_, Path>, CustomError> {
+        let maybe_repo_directory = self.output_directory.as_deref().map(Cow::Borrowed);
+        if let Some(work_dir) = maybe_repo_directory {
             return Ok(work_dir);
         }
         let current_dir: PathBuf = std::env::current_dir()?;

src/config/target.rs

@@ -24,7 +24,7 @@ pub(crate) struct TargetConfig {
     pub(super) path: Option<String>,
 
     #[serde(default)]
-    pub(super) attr: Option<String>,
+    pub(super) attr: String,
 
     #[serde(default)]
     pub(super) update: Option<bool>,
@@ -34,26 +34,44 @@ pub(crate) struct TargetConfig {
 }
 
 impl TargetConfig {
+    /// The root directory for this specific build target.
     pub(crate) fn get_target_directory<'target, 'root>(
         &'target self,
         config_root: &'root Config,
     ) -> Result<Cow<'target, Path>, CustomError> {
-        let work_directory = config_root.get_work_directory()?;
-        Ok(Cow::Owned(work_directory.join(&self.name)))
+        let repo_directory = config_root.get_output_directory()?;
+        Ok(Cow::Owned(repo_directory.join(&self.name)))
     }
 
-    pub(crate) fn get_flake_directory<'target, 'root>(
+    /// The root of the checkout of the git repository.
+    pub(crate) fn get_repo_directory<'target, 'root>(
         &'target self,
         config_root: &'root Config,
     ) -> Result<Cow<'target, Path>, CustomError> {
         let target_directory = self.get_target_directory(config_root)?;
-        Ok(Cow::Owned(target_directory.join("flake")))
+        Ok(Cow::Owned(target_directory.join("repo")))
     }
 
+    /// The directory that contains flake.nix.
+    pub(crate) fn get_flake_directory<'target, 'root>(
+        &'target self,
+        config_root: &'root Config,
+    ) -> Result<Cow<'target, Path>, CustomError> {
+        let repo_directory = self.get_repo_directory(config_root)?;
+        let subpath = self.path.as_deref();
+        if let Some(subpath) = subpath {
+            Ok(Cow::Owned(repo_directory.join(subpath)))
+        } else {
+            Ok(repo_directory)
+        }
+    }
+
+    /// The URL to the upstream git repository.
     pub(crate) fn get_repo(&'_ self) -> Result<&String, CustomError> {
         Ok(&self.repo)
     }
 
+    /// The git branch name to track.
     pub(crate) fn get_branch(&'_ self) -> Result<Cow<'_, str>, CustomError> {
         if let Some(b) = &self.branch {
             Ok(Cow::Borrowed(b))
@@ -62,7 +80,22 @@ impl TargetConfig {
         }
     }
 
+    /// If we want to pin to a specific revision, this is the reference to that commit.
     pub(crate) fn get_revision(&self) -> Result<&Option<String>, CustomError> {
         Ok(&self.revision)
     }
+
+    /// The folder where nixos-rebuild is invoked and the outputs are linked.
+    pub(crate) fn get_build_directory<'target, 'root>(
+        &'target self,
+        config_root: &'root Config,
+    ) -> Result<Cow<'target, Path>, CustomError> {
+        let target_directory = self.get_target_directory(config_root)?;
+        Ok(Cow::Owned(target_directory.join("build")))
+    }
+
+    /// The flake output attribute to build (the part after '#' in the build command).
+    pub(crate) fn get_attr(&'_ self) -> Result<&String, CustomError> {
+        Ok(&self.attr)
+    }
 }