adjust default git clone command

syncat/src/language.rs

@@ -53,9 +53,16 @@ impl<'a> IntoIterator for &'a LangMap {
 pub struct Lang {
     /// The URL of the Git repository with the source for this language.
     pub source: String,
+    /// Additional arguments to supply to `git clone` when installing this language's repository.
+    pub clone_args: Option<Vec<String>>,
+    /// Additional arguments to supply to `git clone` when updating this language's repository.
+    pub pull_args: Option<Vec<String>>,
     /// The path within the repository to the Tree-Sitter language package.
     pub path: Option<PathBuf>,
     /// The name of the directory that the repository is cloned into.
+    ///
+    /// This may be a path relative to the languages.toml file, or an absolute
+    /// path to any directory.
     pub library: PathBuf,
     /// The name of this language, as will be found in the function within the library.
     /// This can be found by running `nm libsyncat.so`, and is typically the same as the
@@ -88,7 +95,10 @@ impl Lang {
         if self.lib.borrow().is_some() {
             return Ok(true);
         }
-        let mut lib_dir = config.libraries().join(&self.library);
+        let mut lib_dir = self.library.clone();
+        if lib_dir.is_relative() {
+            lib_dir = config.libraries().join(lib_dir);
+        }
         if let Some(ref path) = self.path {
             lib_dir = lib_dir.join(path);
         }

syncat/src/package_manager.rs

@@ -57,14 +57,19 @@ impl Installer<'_> {
                 .join(directory);
         }
         if directory.exists() {
-            self.try_command(Command::new("git").arg("pull").current_dir(&directory))?;
+            self.try_command(
+                Command::new("git")
+                    .arg("pull")
+                    .args(self.lang.pull_args.as_ref().unwrap_or(&vec![]))
+                    .current_dir(&directory),
+            )?;
         } else {
             self.try_command(
                 Command::new("git")
                     .arg("clone")
                     .arg(&self.lang.source)
-                    .arg("--recurse") // doubt it's needed, but why not?
                     .arg(&self.lang.library) // make sure we put it in the directory named as expected
+                    .args(self.lang.clone_args.as_ref().unwrap_or(&vec![]))
                     .current_dir(self.config.libraries()),
             )?;
         }