don't default to recursive submodule updates

crates/cli/src/utils/mod.rs

@@ -563,6 +563,7 @@ https://github.com/foundry-rs/foundry/issues/new/choose"
         force: bool,
         remote: bool,
         no_fetch: bool,
+        recursive: bool,
         paths: I,
     ) -> Result<()>
     where
@@ -571,16 +572,27 @@ https://github.com/foundry-rs/foundry/issues/new/choose"
     {
         self.cmd()
             .stderr(self.stderr())
-            .args(["submodule", "update", "--progress", "--init", "--recursive"])
+            .args(["submodule", "update", "--progress", "--init"])
             .args(self.shallow.then_some("--depth=1"))
             .args(force.then_some("--force"))
             .args(remote.then_some("--remote"))
             .args(no_fetch.then_some("--no-fetch"))
+            .args(recursive.then_some("--recursive"))
             .args(paths)
             .exec()
             .map(drop)
     }
 
+    pub fn submodule_foreach(self, recursive: bool, cmd: impl AsRef<OsStr>) -> Result<()> {
+        self.cmd()
+            .stderr(self.stderr())
+            .args(["submodule", "foreach"])
+            .args(recursive.then_some("--recursive"))
+            .arg(cmd)
+            .exec()
+            .map(drop)
+    }
+
     pub fn submodule_init(self) -> Result<()> {
         self.cmd().stderr(self.stderr()).args(["submodule", "init"]).exec().map(drop)
     }

crates/forge/bin/cmd/init.rs

@@ -84,7 +84,7 @@ impl InitArgs {
                 git.submodule_init()?;
             } else {
                 // if not shallow, initialize and clone submodules (without fetching latest)
-                git.submodule_update(false, false, true, None::<PathBuf>)?;
+                git.submodule_update(false, false, true, true, None::<PathBuf>)?;
             }
         } else {
             // if target is not empty

crates/forge/bin/cmd/install.rs

@@ -126,7 +126,8 @@ impl DependencyInstallOpts {
 
         if dependencies.is_empty() && !self.no_git {
             p_println!(!self.quiet => "Updating dependencies in {}", libs.display());
-            git.submodule_update(false, false, false, Some(&libs))?;
+            // recursively fetch all submodules (without fetching latest)
+            git.submodule_update(false, false, false, true, Some(&libs))?;
         }
         fs::create_dir_all(&libs)?;
 
@@ -303,8 +304,8 @@ impl Installer<'_> {
         trace!(?dep, url, ?path, "installing git submodule");
         self.git.submodule_add(true, url, path)?;
 
-        trace!("updating submodule recursively");
-        self.git.submodule_update(false, false, false, Some(path))
+        trace!("initializing submodule recursively");
+        self.git.submodule_update(false, false, false, true, Some(path))
     }
 
     fn git_checkout(self, dep: &Dependency, path: &Path, recurse: bool) -> Result<String> {

crates/forge/bin/cmd/update.rs

@@ -23,14 +23,29 @@ pub struct UpdateArgs {
     /// Override the up-to-date check.
     #[clap(short, long)]
     force: bool,
+
+    /// Recursively update submodules.
+    #[clap(short, long)]
+    recursive: bool,
 }
 impl_figment_convert_basic!(UpdateArgs);
 
 impl UpdateArgs {
     pub fn run(self) -> Result<()> {
         let config = self.try_load_config_emit_warnings()?;
         let (root, paths) = dependencies_paths(&self.dependencies, &config)?;
-        Git::new(&root).submodule_update(self.force, true, false, paths)
+        // fetch the latest changes for each submodule (recursively if flag is set)
+        let git = Git::new(&root);
+        if self.recursive {
+            // update submodules recursively
+            git.submodule_update(self.force, true, false, true, paths)
+        } else {
+            // update root submodules
+            git.submodule_update(self.force, true, false, false, paths)?;
+            // initialize submodules of each submodule recursively (otherwise direct submodule
+            // dependencies will revert to last commit)
+            git.submodule_foreach(false, "git submodule update --init --progress --recursive ")
+        }
     }
 }