refactor(io): share IOInterface via Rc<RefCell<dyn _>> handle

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

31 files changed, 171 insertions, 111 deletions

diff --git a/crates/shirabe/src/command/about_command.rs b/crates/shirabe/src/command/about_command.rs
index ddb9f12..3e74d6e 100644
--- a/crates/shirabe/src/command/about_command.rs
+++ b/crates/shirabe/src/command/about_command.rs
@@ -6,6 +6,7 @@ use crate::command::HasBaseCommandData;
 use crate::composer;
 use crate::composer::ComposerHandle;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use shirabe_external_packages::symfony::component::console::input::InputInterface;
 use shirabe_external_packages::symfony::component::console::output::OutputInterface;
 
diff --git a/crates/shirabe/src/command/archive_command.rs b/crates/shirabe/src/command/archive_command.rs
index 1b21242..225b092 100644
--- a/crates/shirabe/src/command/archive_command.rs
+++ b/crates/shirabe/src/command/archive_command.rs
@@ -14,6 +14,7 @@ use crate::console::input::InputArgument;
 use crate::console::input::InputOption;
 use crate::factory::Factory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::package::archiver::ArchiveManager;
 use crate::package::version::VersionParser;
 use crate::package::version::VersionSelector;
@@ -111,9 +112,9 @@ impl ArchiveCommand {
             });
 
         // TODO(phase-b): clone_box to release self borrow held by get_io.
-        let mut io_box = self.get_io().clone_box();
+        let io_box = self.get_io().clone();
         let return_code = self.archive(
-            io_box.as_mut(),
+            io_box.clone(),
             &config,
             input
                 .get_argument("package")
@@ -153,7 +154,7 @@ impl ArchiveCommand {
 
     pub fn archive(
         &mut self,
-        io: &mut dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         config: &std::rc::Rc<std::cell::RefCell<Config>>,
         package_name: Option<String>,
         version: Option<String>,
@@ -173,12 +174,17 @@ impl ArchiveCommand {
             &composer_archive_manager_ref
         } else {
             let factory = Factory;
-            let process = std::rc::Rc::new(std::cell::RefCell::new(ProcessExecutor::new(())));
+            let process = std::rc::Rc::new(std::cell::RefCell::new(ProcessExecutor::new(None)));
             let http_downloader = std::rc::Rc::new(std::cell::RefCell::new(
-                Factory::create_http_downloader(io, config, indexmap::IndexMap::new())?,
+                Factory::create_http_downloader(io.clone(), config, indexmap::IndexMap::new())?,
             ));
-            let download_manager =
-                factory.create_download_manager(io, config, &http_downloader, &process, None)?;
+            let download_manager = factory.create_download_manager(
+                io.clone(),
+                config,
+                &http_downloader,
+                &process,
+                None,
+            )?;
             let loop_ = std::rc::Rc::new(std::cell::RefCell::new(Loop::new(
                 http_downloader.clone(),
                 Some(process),
@@ -190,7 +196,7 @@ impl ArchiveCommand {
 
         let package: crate::package::CompletePackageInterfaceHandle =
             if let Some(name) = package_name {
-                match self.select_package(io, &name, version.as_deref())? {
+                match self.select_package(io.clone(), &name, version.as_deref())? {
                     Some(p) => p,
                     None => return Ok(1),
                 }
@@ -227,7 +233,7 @@ impl ArchiveCommand {
 
     pub fn select_package(
         &mut self,
-        io: &mut dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         package_name: &str,
         version: Option<&str>,
     ) -> Result<Option<crate::package::CompletePackageInterfaceHandle>> {
@@ -253,7 +259,7 @@ impl ArchiveCommand {
             repo = CompositeRepository::new(repos);
             min_stability = composer.get_package().get_minimum_stability().to_string();
         } else {
-            let default_repos = RepositoryFactory::default_repos_with_default_manager(io)?;
+            let default_repos = RepositoryFactory::default_repos_with_default_manager(io.clone())?;
             let repo_names: Vec<String> = default_repos.keys().cloned().collect();
             io.write_error(&format!(
                 "No composer.json found in the current directory, searching packages from {}",
diff --git a/crates/shirabe/src/command/audit_command.rs b/crates/shirabe/src/command/audit_command.rs
index d3dadbd..ec8b495 100644
--- a/crates/shirabe/src/command/audit_command.rs
+++ b/crates/shirabe/src/command/audit_command.rs
@@ -6,6 +6,7 @@ use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::composer::PartialComposerHandle;
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::repository::CanonicalPackagesTrait;
 use crate::repository::InstalledRepository;
 use crate::repository::RepositoryInterface;
@@ -127,7 +128,7 @@ impl AuditCommand {
         let _ = ignore_severities;
         Ok(auditor
             .audit(
-                self.get_io(),
+                &mut *self.get_io().borrow_mut(),
                 &repo_set,
                 packages,
                 &audit_format,
diff --git a/crates/shirabe/src/command/base_command.rs b/crates/shirabe/src/command/base_command.rs
index 9511c4d..6b673ed 100644
--- a/crates/shirabe/src/command/base_command.rs
+++ b/crates/shirabe/src/command/base_command.rs
@@ -13,6 +13,8 @@ use shirabe_php_shim::{
     InvalidArgumentException, LogicException, PhpMixed, RuntimeException, UnexpectedValueException,
     count, explode, in_array, is_string, max,
 };
+use std::cell::RefCell;
+use std::rc::Rc;
 
 use crate::advisory::AuditConfig;
 use crate::advisory::Auditor;
@@ -27,6 +29,7 @@ use crate::factory::Factory;
 use crate::filter::platform_requirement_filter::PlatformRequirementFilterFactory;
 use crate::filter::platform_requirement_filter::PlatformRequirementFilterInterface;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::io::NullIO;
 use crate::package::version::VersionParser;
 use crate::plugin::PluginEvents;
@@ -184,9 +187,9 @@ pub trait BaseCommand {
     /// Whether or not this command is meant to call another command.
     fn is_proxy_command(&self) -> bool;
 
-    fn get_io(&mut self) -> &mut dyn IOInterface;
+    fn get_io(&mut self) -> Rc<RefCell<dyn IOInterface>>;
 
-    fn set_io(&mut self, io: Box<dyn IOInterface>);
+    fn set_io(&mut self, io: Rc<RefCell<dyn IOInterface>>);
 
     // TODO(cli-completion): fn complete(&self, input: &CompletionInput, suggestions: &mut CompletionSuggestions);
 
@@ -201,7 +204,7 @@ pub trait BaseCommand {
     fn create_composer_instance(
         &self,
         input: &dyn InputInterface,
-        io: &dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         config: Option<IndexMap<String, PhpMixed>>,
         disable_plugins: bool,
         disable_scripts: Option<bool>,
@@ -254,7 +257,7 @@ pub trait BaseCommand {
 #[derive(Debug)]
 pub struct BaseCommandData {
     pub(crate) composer: Option<PartialComposerHandle>,
-    pub(crate) io: Option<Box<dyn IOInterface>>,
+    pub(crate) io: Option<Rc<RefCell<dyn IOInterface>>>,
 }
 
 pub trait HasBaseCommandData {
@@ -269,11 +272,11 @@ pub trait HasBaseCommandData {
         &mut self.base_command_data_mut().composer
     }
 
-    fn io(&self) -> Option<&dyn IOInterface> {
-        self.base_command_data().io.as_deref()
+    fn io(&self) -> Option<Rc<RefCell<dyn IOInterface>>> {
+        self.base_command_data().io.clone()
     }
 
-    fn io_mut(&mut self) -> &mut Option<Box<dyn IOInterface>> {
+    fn io_mut(&mut self) -> &mut Option<Rc<RefCell<dyn IOInterface>>> {
         &mut self.base_command_data_mut().io
     }
 }
@@ -335,16 +338,16 @@ impl<C: HasBaseCommandData> BaseCommand for C {
         false
     }
 
-    fn get_io(&mut self) -> &mut dyn IOInterface {
+    fn get_io(&mut self) -> Rc<RefCell<dyn IOInterface>> {
         if self.io().is_none() {
             // TODO(phase-b): requires inner Symfony Application access
-            *self.io_mut() = Some(Box::new(NullIO::new()));
+            *self.io_mut() = Some(Rc::new(RefCell::new(NullIO::new())));
         }
 
-        &mut **self.io_mut().as_mut().unwrap()
+        self.io().unwrap()
     }
 
-    fn set_io(&mut self, io: Box<dyn IOInterface>) {
+    fn set_io(&mut self, io: Rc<RefCell<dyn IOInterface>>) {
         *self.io_mut() = Some(io);
     }
 
@@ -363,9 +366,7 @@ impl<C: HasBaseCommandData> BaseCommand for C {
         // TODO(phase-b): `$this instanceof SelfUpdateCommand` not representable
 
         let composer = self.try_composer(Some(disable_plugins), Some(disable_scripts));
-        // TODO(phase-b): re-borrow self for get_io after try_composer move
-        let io_ptr: *const dyn IOInterface = self.get_io();
-        let io = unsafe { &*io_ptr };
+        let io = self.get_io();
 
         let disable_plugins_kind = if disable_plugins {
             crate::factory::DisablePlugins::All
@@ -373,7 +374,7 @@ impl<C: HasBaseCommandData> BaseCommand for C {
             crate::factory::DisablePlugins::None
         };
         let composer = if composer.is_none() {
-            Factory::create_global(io, disable_plugins_kind, disable_scripts)
+            Factory::create_global(io.clone(), disable_plugins_kind, disable_scripts)
         } else {
             composer
         };
@@ -476,7 +477,7 @@ impl<C: HasBaseCommandData> BaseCommand for C {
     fn create_composer_instance(
         &self,
         input: &dyn InputInterface,
-        io: &dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         config: Option<IndexMap<String, PhpMixed>>,
         disable_plugins: bool,
         disable_scripts: Option<bool>,
diff --git a/crates/shirabe/src/command/base_config_command.rs b/crates/shirabe/src/command/base_config_command.rs
index 85e68b3..1b7294e 100644
--- a/crates/shirabe/src/command/base_config_command.rs
+++ b/crates/shirabe/src/command/base_config_command.rs
@@ -37,9 +37,9 @@ pub trait BaseConfigCommand: BaseCommand {
         }
 
         // TODO(phase-b): clone_box to release the &mut self borrow held by get_io.
-        let io = self.get_io().clone_box();
+        let io = self.get_io().clone();
         *self.config_mut() = Some(std::rc::Rc::new(std::cell::RefCell::new(
-            Factory::create_config(Some(io.as_ref()), None)?,
+            Factory::create_config(Some(io.clone()), None)?,
         )));
         let config_rc = self.config().unwrap().clone();
 
@@ -62,7 +62,7 @@ pub trait BaseConfigCommand: BaseCommand {
         self.set_config_file(Some(JsonFile::new(
             config_file.clone(),
             None,
-            Some(io.clone_box()),
+            Some(io.clone()),
         )?));
         // TODO(phase-b): JsonConfigSource::new takes owned JsonFile, but PHP shares the same
         // instance with $this->configFile. Needs Rc<RefCell<JsonFile>> refactor on both sides.
diff --git a/crates/shirabe/src/command/base_dependency_command.rs b/crates/shirabe/src/command/base_dependency_command.rs
index 8ea10b5..f449629 100644
--- a/crates/shirabe/src/command/base_dependency_command.rs
+++ b/crates/shirabe/src/command/base_dependency_command.rs
@@ -10,6 +10,8 @@ use shirabe_semver::constraint::AnyConstraint;
 use shirabe_semver::constraint::Bound;
 
 use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
+use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::package::CompletePackageInterface;
 use crate::package::Link;
 use crate::package::Package;
diff --git a/crates/shirabe/src/command/check_platform_reqs_command.rs b/crates/shirabe/src/command/check_platform_reqs_command.rs
index 5d886e7..fd5edd9 100644
--- a/crates/shirabe/src/command/check_platform_reqs_command.rs
+++ b/crates/shirabe/src/command/check_platform_reqs_command.rs
@@ -11,6 +11,7 @@ use shirabe_semver::constraint::SimpleConstraint;
 use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::Link;
 use crate::repository::InstalledRepository;
diff --git a/crates/shirabe/src/command/config_command.rs b/crates/shirabe/src/command/config_command.rs
index 6412160..476be75 100644
--- a/crates/shirabe/src/command/config_command.rs
+++ b/crates/shirabe/src/command/config_command.rs
@@ -25,6 +25,7 @@ use crate::config::JsonConfigSource;
 use crate::console::input::InputArgument;
 use crate::factory::Factory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::base_package::{self, BasePackage};
 use crate::util::Filesystem;
@@ -130,7 +131,7 @@ impl ConfigCommand {
         self.auth_config_file = Some(JsonFile::new(
             auth_config_file,
             None,
-            Some(self.get_io().clone_box()),
+            Some(self.get_io().clone()),
         )?);
         // TODO(phase-b): JsonConfigSource::new takes owned JsonFile (PHP sharing semantics).
         // Skipping auth_config_source assignment until Rc<RefCell<JsonFile>> refactor lands.
@@ -257,6 +258,7 @@ impl ConfigCommand {
         {
             let config_rc = self.config.as_ref().unwrap().clone();
             self.get_io()
+                .borrow_mut()
                 .load_configuration(&mut *config_rc.borrow_mut())?;
         }
 
diff --git a/crates/shirabe/src/command/create_project_command.rs b/crates/shirabe/src/command/create_project_command.rs
index e0cb3d4..d5a8a0c 100644
--- a/crates/shirabe/src/command/create_project_command.rs
+++ b/crates/shirabe/src/command/create_project_command.rs
@@ -30,6 +30,7 @@ use crate::installer::Installer;
 use crate::installer::ProjectInstaller;
 use crate::installer::SuggestedPackagesReporter;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::version::VersionParser;
 use crate::package::version::VersionSelector;
@@ -113,7 +114,7 @@ impl CreateProjectCommand {
     ) -> Result<i64> {
         let config = std::rc::Rc::new(std::cell::RefCell::new(Factory::create_config(None, None)?));
         // TODO(phase-b): get_io returns &mut Self-borrow; clone_box for an owned Box to dodge.
-        let io: Box<dyn IOInterface> = self.get_io().clone_box();
+        let io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>> = self.get_io().clone();
 
         let (prefer_source, prefer_dist) =
             self.get_preferred_install_options(&config.borrow(), input, true)?;
@@ -160,9 +161,8 @@ impl CreateProjectCommand {
             Some(repository_url_opt)
         };
 
-        let mut io = io;
         self.install_project(
-            &mut *io,
+            io,
             config,
             input,
             input
@@ -207,7 +207,7 @@ impl CreateProjectCommand {
     #[allow(clippy::too_many_arguments)]
     pub fn install_project(
         &mut self,
-        io: &mut dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         config: std::rc::Rc<std::cell::RefCell<Config>>,
         input: &dyn InputInterface,
         package_name: Option<String>,
@@ -247,14 +247,15 @@ impl CreateProjectCommand {
             .unwrap_or_else(PlatformRequirementFilterFactory::ignore_nothing);
 
         // we need to manually load the configuration to pass the auth credentials to the io interface!
-        io.load_configuration(&mut *config.borrow_mut())?;
+        io.borrow_mut()
+            .load_configuration(&mut *config.borrow_mut())?;
 
-        self.suggested_packages_reporter = Some(SuggestedPackagesReporter::new(io.clone_box()));
+        self.suggested_packages_reporter = Some(SuggestedPackagesReporter::new(io.clone()));
 
         let installed_from_vcs = if let Some(package_name) = package_name.as_ref() {
             self.install_root_package(
                 input,
-                io,
+                io.clone(),
                 &config,
                 package_name,
                 &*platform_requirement_filter,
@@ -278,8 +279,13 @@ impl CreateProjectCommand {
             unlink("composer.lock");
         }
 
-        let mut composer_handle =
-            self.create_composer_instance(input, io, None, disable_plugins, Some(disable_scripts))?;
+        let mut composer_handle = self.create_composer_instance(
+            input,
+            io.clone(),
+            None,
+            disable_plugins,
+            Some(disable_scripts),
+        )?;
 
         // add the repository to the composer.json and use it for the install run later
         if let Some(repos) = repositories.as_ref() {
@@ -287,7 +293,7 @@ impl CreateProjectCommand {
                 for (index, repo) in repos.iter().enumerate() {
                     let config = crate::command::composer_full(&composer_handle).get_config();
                     let repo_config =
-                        RepositoryFactory::config_from_string(io, &config, repo, true)?;
+                        RepositoryFactory::config_from_string(io.clone(), &config, repo, true)?;
                     let composer_json_repositories_config =
                         crate::command::composer_full(&composer_handle)
                             .get_config()
@@ -332,8 +338,13 @@ impl CreateProjectCommand {
                         );
                     }
 
-                    composer_handle =
-                        self.create_composer_instance(input, io, None, disable_plugins, None)?;
+                    composer_handle = self.create_composer_instance(
+                        input,
+                        io.clone(),
+                        None,
+                        disable_plugins,
+                        None,
+                    )?;
                 }
             }
         }
@@ -371,7 +382,7 @@ impl CreateProjectCommand {
                 .borrow_mut()
                 .set_output_progress(!no_progress);
 
-            let mut installer = Installer::create(io.clone_box(), &composer_handle);
+            let mut installer = Installer::create(io.clone(), &composer_handle);
             // TODO(phase-b): set_suggested_packages_reporter takes by value but PHP class
             // means shared ownership; needs Rc<SuggestedPackagesReporter> for proper sharing.
             installer
@@ -379,7 +390,7 @@ impl CreateProjectCommand {
                 .set_prefer_dist(prefer_dist)
                 .set_dev_mode(install_dev_packages)
                 .set_platform_requirement_filter(platform_requirement_filter.clone_box())
-                .set_suggested_packages_reporter(SuggestedPackagesReporter::new(io.clone_box()))
+                .set_suggested_packages_reporter(SuggestedPackagesReporter::new(io.clone()))
                 .set_optimize_autoloader(
                     config
                         .borrow_mut()
@@ -540,7 +551,7 @@ impl CreateProjectCommand {
     fn install_root_package(
         &self,
         input: &dyn InputInterface,
-        io: &dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         config: &std::rc::Rc<std::cell::RefCell<Config>>,
         package_name: &str,
         platform_requirement_filter: &dyn PlatformRequirementFilterInterface,
@@ -584,7 +595,7 @@ impl CreateProjectCommand {
         directory = rtrim(&directory, Some("/\\"));
 
         let process = std::rc::Rc::new(std::cell::RefCell::new(ProcessExecutor::new(Some(
-            io.clone_box(),
+            io.clone(),
         ))));
         let fs = std::rc::Rc::new(std::cell::RefCell::new(Filesystem::new(Some(process))));
         if !fs.borrow().is_absolute_path(&directory) {
@@ -704,7 +715,7 @@ impl CreateProjectCommand {
 
         let composer_handle = self.create_composer_instance(
             input,
-            io,
+            io.clone(),
             Some(config.borrow_mut().all(0)?),
             disable_plugins,
             Some(disable_scripts),
@@ -727,7 +738,7 @@ impl CreateProjectCommand {
             // TODO(phase-b): default_repos needs &mut RepositoryManager but we hold &RepositoryManager.
             let _ = rm;
             repository_set.add_repository(Box::new(CompositeRepository::new(
-                RepositoryFactory::default_repos(Some(io), Some(config.clone()), None)?
+                RepositoryFactory::default_repos(Some(io.clone()), Some(config.clone()), None)?
                     .into_iter()
                     .map(|(_, v)| v)
                     .collect(),
@@ -735,7 +746,7 @@ impl CreateProjectCommand {
         } else {
             for repo in repositories.unwrap() {
                 let mut repo_config =
-                    RepositoryFactory::config_from_string(io, &config, repo, true)?;
+                    RepositoryFactory::config_from_string(io.clone(), &config, repo, true)?;
                 let is_packagist_disabled = (repo_config.contains_key("packagist")
                     && repo_config.len() == 1
                     && repo_config.get("packagist").and_then(|v| v.as_bool()) == Some(false))
@@ -767,7 +778,7 @@ impl CreateProjectCommand {
                 }
 
                 repository_set.add_repository(RepositoryFactory::create_repo(
-                    io,
+                    io.clone(),
                     &config,
                     repo_config.clone(),
                     None,
@@ -803,7 +814,7 @@ impl CreateProjectCommand {
             &stability,
             None,
             0,
-            Some(io),
+            Some(&*io.borrow()),
             PhpMixed::Bool(true),
         )?;
 
@@ -913,7 +924,7 @@ impl CreateProjectCommand {
             true,
             false,
         )?;
-        im.notify_installs(io);
+        im.notify_installs(&*io.borrow());
 
         // collect suggestions
         // TODO(phase-b): self.suggested_packages_reporter is on the outer scope via &self
@@ -947,7 +958,7 @@ impl CreateProjectCommand {
     fn create_composer_instance(
         &self,
         input: &dyn InputInterface,
-        io: &dyn IOInterface,
+        io: std::rc::Rc<std::cell::RefCell<dyn IOInterface>>,
         config: Option<indexmap::IndexMap<String, PhpMixed>>,
         disable_plugins: bool,
         disable_scripts: Option<bool>,
diff --git a/crates/shirabe/src/command/diagnose_command.rs b/crates/shirabe/src/command/diagnose_command.rs
index fe57e5c..c64fc39 100644
--- a/crates/shirabe/src/command/diagnose_command.rs
+++ b/crates/shirabe/src/command/diagnose_command.rs
@@ -27,6 +27,7 @@ use crate::downloader::TransportException;
 use crate::factory::Factory;
 use crate::io::BufferIO;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::io::NullIO;
 use crate::json::JsonFile;
 use crate::json::JsonValidationException;
@@ -78,7 +79,7 @@ impl DiagnoseCommand {
         output: &dyn OutputInterface,
     ) -> anyhow::Result<i64> {
         let mut composer = self.try_composer(None, None);
-        let io_boxed: Box<dyn IOInterface> = self.get_io().clone_box();
+        let io_boxed: std::rc::Rc<std::cell::RefCell<dyn IOInterface>> = self.get_io().clone();
 
         let config: std::rc::Rc<std::cell::RefCell<Config>>;
         if let Some(ref mut c) = composer {
@@ -103,7 +104,7 @@ impl DiagnoseCommand {
                     .map(std::rc::Rc::clone)
                     .unwrap_or_else(|| {
                         std::rc::Rc::new(std::cell::RefCell::new(ProcessExecutor::new(Some(
-                            io_boxed.clone_box(),
+                            io_boxed.clone(),
                         ))))
                     }),
             );
@@ -111,12 +112,13 @@ impl DiagnoseCommand {
             config = std::rc::Rc::new(std::cell::RefCell::new(Factory::create_config(None, None)?));
 
             self.process = Some(std::rc::Rc::new(std::cell::RefCell::new(
-                ProcessExecutor::new(Some(io_boxed.clone_box())),
+                ProcessExecutor::new(Some(io_boxed.clone())),
             )));
         }
         // TODO(phase-b): clone_box to release self borrow held by get_io.
-        let io_box = self.get_io().clone_box();
-        let io: &dyn IOInterface = io_box.as_ref();
+        let io_box = self.get_io().clone();
+        let io_ref = io_box.borrow();
+        let io: &dyn IOInterface = &*io_ref;
 
         let mut config_inner: IndexMap<String, Box<PhpMixed>> = IndexMap::new();
         config_inner.insert("secure-http".to_string(), Box::new(PhpMixed::Bool(false)));
@@ -133,7 +135,7 @@ impl DiagnoseCommand {
         );
 
         self.http_downloader = Some(std::rc::Rc::new(std::cell::RefCell::new(
-            Factory::create_http_downloader(io, &config, indexmap::IndexMap::new())?,
+            Factory::create_http_downloader(io_box.clone(), &config, indexmap::IndexMap::new())?,
         )));
 
         if strpos(file!(), "phar:") == Some(0) {
@@ -295,7 +297,7 @@ impl DiagnoseCommand {
                     .collect();
                 let composer_repo = ComposerRepository::new(
                     repo_arr_unboxed,
-                    self.get_io().clone_box(),
+                    self.get_io().clone(),
                     &*config.borrow(),
                     self.http_downloader.clone().unwrap(),
                     None,
@@ -427,7 +429,7 @@ impl DiagnoseCommand {
     }
 
     fn check_composer_schema(&mut self) -> anyhow::Result<PhpMixed> {
-        let validator = ConfigValidator::new(self.get_io().clone_box());
+        let validator = ConfigValidator::new(self.get_io().clone());
         let (errors, _, warnings) = validator.validate(&Factory::get_composer_file()?, 0, 0);
 
         if !errors.is_empty() || !warnings.is_empty() {
@@ -680,7 +682,7 @@ impl DiagnoseCommand {
             return Ok(result);
         }
 
-        self.get_io().set_authentication(
+        self.get_io().borrow_mut().set_authentication(
             domain.to_string(),
             token.to_string(),
             Some("x-oauth-basic".to_string()),
@@ -744,7 +746,7 @@ impl DiagnoseCommand {
         }
 
         if let Some(t) = token {
-            self.get_io().set_authentication(
+            self.get_io().borrow_mut().set_authentication(
                 domain.to_string(),
                 t.to_string(),
                 Some("x-oauth-basic".to_string()),
@@ -939,7 +941,7 @@ impl DiagnoseCommand {
         // TODO(phase-b): ComposerRepository does not implement RepositoryInterface yet
         let _composer_repo = ComposerRepository::new(
             repo_config,
-            Box::new(NullIO::new()),
+            std::rc::Rc::new(std::cell::RefCell::new(NullIO::new())),
             config,
             self.http_downloader.clone().unwrap(),
             None,
diff --git a/crates/shirabe/src/command/dump_autoload_command.rs b/crates/shirabe/src/command/dump_autoload_command.rs
index 275e635..6f361da 100644
--- a/crates/shirabe/src/command/dump_autoload_command.rs
+++ b/crates/shirabe/src/command/dump_autoload_command.rs
@@ -8,6 +8,7 @@ use shirabe_php_shim::{InvalidArgumentException, PhpMixed, file_exists};
 use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::plugin::CommandEvent;
 use crate::plugin::PluginEvents;
 
diff --git a/crates/shirabe/src/command/exec_command.rs b/crates/shirabe/src/command/exec_command.rs
index 23aa103..3f70cf8 100644
--- a/crates/shirabe/src/command/exec_command.rs
+++ b/crates/shirabe/src/command/exec_command.rs
@@ -9,6 +9,7 @@ use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputArgument;
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 
 #[derive(Debug)]
 pub struct ExecCommand {
diff --git a/crates/shirabe/src/command/fund_command.rs b/crates/shirabe/src/command/fund_command.rs
index f829342..340424f 100644
--- a/crates/shirabe/src/command/fund_command.rs
+++ b/crates/shirabe/src/command/fund_command.rs
@@ -15,6 +15,7 @@ use shirabe_semver::constraint::MatchAllConstraint;
 use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::AliasPackage;
 use crate::package::CompletePackage;
diff --git a/crates/shirabe/src/command/global_command.rs b/crates/shirabe/src/command/global_command.rs
index a8cf1d4..a3d5a78 100644
--- a/crates/shirabe/src/command/global_command.rs
+++ b/crates/shirabe/src/command/global_command.rs
@@ -13,6 +13,7 @@ use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputArgument;
 use crate::factory::Factory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::util::Filesystem;
 use crate::util::Platform;
 
diff --git a/crates/shirabe/src/command/home_command.rs b/crates/shirabe/src/command/home_command.rs
index 673039a..c048bfd 100644
--- a/crates/shirabe/src/command/home_command.rs
+++ b/crates/shirabe/src/command/home_command.rs
@@ -9,6 +9,7 @@ use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputArgument;
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::package::CompletePackageInterfaceHandle;
 use crate::package::PackageInterface;
 use crate::package::RootPackageInterface;
@@ -73,8 +74,9 @@ impl HomeCommand {
     ) -> Result<i64> {
         let repos = self.initialize_repos()?;
         // TODO(phase-b): clone_box to release self borrow held by get_io.
-        let io_box = self.get_io().clone_box();
-        let io: &dyn IOInterface = io_box.as_ref();
+        let io_box = self.get_io().clone();
+        let io_ref = io_box.borrow();
+        let io: &dyn IOInterface = &*io_ref;
         let mut return_code: i64 = 0;
 
         let packages: Vec<String> = input
@@ -172,7 +174,7 @@ impl HomeCommand {
     }
 
     fn open_browser(&mut self, url: &str) {
-        let mut process = ProcessExecutor::new(Some(self.get_io().clone_box()));
+        let mut process = ProcessExecutor::new(Some(self.get_io().clone()));
         if Platform::is_windows() {
             let _ = process.execute(
                 PhpMixed::from(vec!["start", "\"web\"", "explorer", url]),
diff --git a/crates/shirabe/src/command/init_command.rs b/crates/shirabe/src/command/init_command.rs
index 122642d..730658c 100644
--- a/crates/shirabe/src/command/init_command.rs
+++ b/crates/shirabe/src/command/init_command.rs
@@ -23,6 +23,7 @@ use crate::composer::PartialComposerHandle;
 use crate::console::input::InputOption;
 use crate::factory::Factory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::json::JsonValidationException;
 use crate::package::base_package::{self, BasePackage};
@@ -52,7 +53,7 @@ impl PackageDiscoveryTrait for InitCommand {
         todo!()
     }
 
-    fn get_io(&self) -> &dyn IOInterface {
+    fn get_io(&self) -> std::rc::Rc<std::cell::RefCell<dyn IOInterface>> {
         todo!()
     }
 
@@ -193,11 +194,12 @@ impl InitCommand {
             .unwrap_or_default();
         if (repositories.len() as i64) > 0 {
             let config = std::rc::Rc::new(std::cell::RefCell::new(Factory::create_config(
-                Some(io),
+                Some(io.clone()),
                 None,
             )?));
             for repo in &repositories {
-                let repo_config = RepositoryFactory::config_from_string(io, &config, repo, true)?;
+                let repo_config =
+                    RepositoryFactory::config_from_string(io.clone(), &config, repo, true)?;
                 let entry = options
                     .entry("repositories".to_string())
                     .or_insert_with(|| PhpMixed::List(vec![]));
@@ -445,17 +447,20 @@ impl InitCommand {
             .unwrap_or_default();
         if (repositories.len() as i64) > 0 {
             let config = std::rc::Rc::new(std::cell::RefCell::new(Factory::create_config(
-                Some(io),
+                Some(io.clone()),
                 None,
             )?));
-            io.load_configuration(&mut *config.borrow_mut())?;
-            let mut repo_manager = RepositoryFactory::manager(io, &config, None, None, None)?;
+            io.borrow_mut()
+                .load_configuration(&mut *config.borrow_mut())?;
+            let mut repo_manager =
+                RepositoryFactory::manager(io.clone(), &config, None, None, None)?;
 
             let mut repos: Vec<Box<dyn crate::repository::RepositoryInterface>> =
                 vec![Box::new(PlatformRepository::new(vec![], IndexMap::new())?)];
             let mut create_default_packagist_repo = true;
             for repo in &repositories {
-                let repo_config = RepositoryFactory::config_from_string(io, &config, repo, true)?;
+                let repo_config =
+                    RepositoryFactory::config_from_string(io.clone(), &config, repo, true)?;
                 let is_packagist_false = repo_config
                     .get("packagist")
                     .map(|v| v.as_bool() == Some(false))
@@ -471,7 +476,7 @@ impl InitCommand {
                     continue;
                 }
                 repos.push(RepositoryFactory::create_repo(
-                    io,
+                    io.clone(),
                     &config,
                     repo_config,
                     Some(&mut repo_manager),
@@ -486,7 +491,7 @@ impl InitCommand {
                     PhpMixed::String("https://repo.packagist.org".to_string()),
                 );
                 repos.push(RepositoryFactory::create_repo(
-                    io,
+                    io.clone(),
                     &config,
                     default_config,
                     Some(&mut repo_manager),
@@ -943,7 +948,7 @@ impl InitCommand {
             return self.git_config.clone().unwrap_or_default();
         }
 
-        let mut process = ProcessExecutor::new(Some(self.get_io().clone_box()));
+        let mut process = ProcessExecutor::new(Some(self.get_io().clone()));
 
         let mut output = String::new();
         if process.execute_args(
diff --git a/crates/shirabe/src/command/install_command.rs b/crates/shirabe/src/command/install_command.rs
index a0710dc..4c869f4 100644
--- a/crates/shirabe/src/command/install_command.rs
+++ b/crates/shirabe/src/command/install_command.rs
@@ -67,8 +67,9 @@ impl InstallCommand {
         output: &dyn OutputInterface,
     ) -> Result<i64> {
         // TODO(phase-b): clone_box to release self borrow held by get_io.
-        let io_box = self.get_io().clone_box();
-        let io: &dyn IOInterface = io_box.as_ref();
+        let io_box = self.get_io().clone();
+        let io_ref = io_box.borrow();
+        let io: &dyn IOInterface = &*io_ref;
 
         if input.get_option("dev").as_bool().unwrap_or(false) {
             io.write_error("<warning>You are using the deprecated option \"--dev\". It has no effect and will break in Composer 3.</warning>");
@@ -114,7 +115,7 @@ impl InstallCommand {
             .borrow_mut()
             .dispatch(Some(command_event.get_name()), None);
 
-        let mut install = Installer::create(io.clone_box(), &composer_handle);
+        let mut install = Installer::create(io_box.clone(), &composer_handle);
 
         let config = composer.get_config();
         let (prefer_source, prefer_dist) =
diff --git a/crates/shirabe/src/command/licenses_command.rs b/crates/shirabe/src/command/licenses_command.rs
index 2bcecd5..6c7ea73 100644
--- a/crates/shirabe/src/command/licenses_command.rs
+++ b/crates/shirabe/src/command/licenses_command.rs
@@ -14,6 +14,7 @@ use shirabe_php_shim::{PhpMixed, RuntimeException, UnexpectedValueException};
 use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::BasePackage;
 use crate::package::CompletePackage;
diff --git a/crates/shirabe/src/command/package_discovery_trait.rs b/crates/shirabe/src/command/package_discovery_trait.rs
index a268469..e8a56a9 100644
--- a/crates/shirabe/src/command/package_discovery_trait.rs
+++ b/crates/shirabe/src/command/package_discovery_trait.rs
@@ -20,6 +20,7 @@ use crate::factory::Factory;
 use crate::filter::platform_requirement_filter::IgnoreAllPlatformRequirementFilter;
 use crate::filter::platform_requirement_filter::PlatformRequirementFilterFactory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::package::BasePackage;
 use crate::package::CompletePackageInterface;
 use crate::package::PackageInterface;
@@ -40,7 +41,7 @@ pub trait PackageDiscoveryTrait {
     fn get_repository_sets_mut(&mut self) -> &mut IndexMap<String, RepositorySet>;
 
     // PHP: trait dependencies (provided by BaseCommand)
-    fn get_io(&self) -> &dyn IOInterface;
+    fn get_io(&self) -> std::rc::Rc<std::cell::RefCell<dyn IOInterface>>;
     fn try_composer(&self) -> Option<PartialComposerHandle>;
     fn require_composer(
         &self,
@@ -61,8 +62,8 @@ pub trait PackageDiscoveryTrait {
                 // TODO(phase-b): PlatformRepository::new() signature
                 Box::new(todo!("PlatformRepository::new()") as PlatformRepository),
             ];
-            let mut io_owned: Box<dyn IOInterface> = todo!("clone self.get_io() into a Box");
-            for (_, repo) in RepositoryFactory::default_repos_with_default_manager(&mut *io_owned)
+            let io_owned: std::rc::Rc<std::cell::RefCell<dyn IOInterface>> = self.get_io();
+            for (_, repo) in RepositoryFactory::default_repos_with_default_manager(io_owned)
                 .unwrap()
                 .into_iter()
             {
diff --git a/crates/shirabe/src/command/reinstall_command.rs b/crates/shirabe/src/command/reinstall_command.rs
index 1e3114b..ad4739b 100644
--- a/crates/shirabe/src/command/reinstall_command.rs
+++ b/crates/shirabe/src/command/reinstall_command.rs
@@ -16,6 +16,7 @@ use crate::dependency_resolver::Transaction;
 use crate::dependency_resolver::operation::InstallOperation;
 use crate::dependency_resolver::operation::UninstallOperation;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::package::base_package;
 use crate::plugin::CommandEvent;
 use crate::plugin::PluginEvents;
diff --git a/crates/shirabe/src/command/remove_command.rs b/crates/shirabe/src/command/remove_command.rs
index 49b21dc..9ea7329 100644
--- a/crates/shirabe/src/command/remove_command.rs
+++ b/crates/shirabe/src/command/remove_command.rs
@@ -17,6 +17,7 @@ use crate::dependency_resolver::Request;
 use crate::factory::Factory;
 use crate::installer::Installer;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::BasePackage;
 use crate::package::base_package;
@@ -510,8 +511,9 @@ impl RemoveCommand {
             .borrow_mut()
             .set_output_progress(!input.get_option("no-progress").as_bool().unwrap_or(false));
 
-        // TODO(phase-b): Installer::create expects Box<dyn IOInterface>; io here is &mut dyn IOInterface
-        let io_box: Box<dyn IOInterface> = todo!("share IOInterface as Box<dyn IOInterface>");
+        // TODO(phase-b): Installer::create expects std::rc::Rc<std::cell::RefCell<dyn IOInterface>>; io here is &mut dyn IOInterface
+        let io_box: std::rc::Rc<std::cell::RefCell<dyn IOInterface>> =
+            todo!("share IOInterface as Box<dyn IOInterface>");
         let mut install = Installer::create(io_box, &composer_handle);
 
         let update_dev_mode = !input.get_option("update-no-dev").as_bool().unwrap_or(false);
diff --git a/crates/shirabe/src/command/repository_command.rs b/crates/shirabe/src/command/repository_command.rs
index 1f6599b..bf000e4 100644
--- a/crates/shirabe/src/command/repository_command.rs
+++ b/crates/shirabe/src/command/repository_command.rs
@@ -17,6 +17,7 @@ use crate::console::input::InputArgument;
 use crate::console::input::InputOption;
 use crate::factory::Factory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 
 #[derive(Debug)]
diff --git a/crates/shirabe/src/command/require_command.rs b/crates/shirabe/src/command/require_command.rs
index f0dce6b..66e1134 100644
--- a/crates/shirabe/src/command/require_command.rs
+++ b/crates/shirabe/src/command/require_command.rs
@@ -25,6 +25,7 @@ use crate::factory::Factory;
 use crate::installer::Installer;
 use crate::installer::InstallerEvents;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::json::JsonManipulator;
 use crate::package::base_package;
@@ -67,7 +68,7 @@ impl PackageDiscoveryTrait for RequireCommand {
         todo!()
     }
 
-    fn get_io(&self) -> &dyn IOInterface {
+    fn get_io(&self) -> std::rc::Rc<std::cell::RefCell<dyn IOInterface>> {
         todo!()
     }
 
@@ -845,10 +846,12 @@ impl RequireCommand {
             .borrow_mut()
             .set_output_progress(!input.get_option("no-progress").as_bool().unwrap_or(false));
 
-        // TODO(phase-b): Installer::create takes Box<dyn IOInterface> for ownership but io is a
+        // TODO(phase-b): Installer::create takes std::rc::Rc<std::cell::RefCell<dyn IOInterface>> for ownership but io is a
         // borrowed &dyn here; needs Rc<dyn IOInterface> for proper sharing.
-        let mut install =
-            Installer::create(todo!("share io as Box<dyn IOInterface>"), &composer_handle);
+        let mut install = Installer::create(
+            todo!("share io as std::rc::Rc<std::cell::RefCell<dyn IOInterface>>"),
+            &composer_handle,
+        );
 
         let (prefer_source, prefer_dist) =
             self.get_preferred_install_options(&*composer.get_config().borrow(), input, false)?;
diff --git a/crates/shirabe/src/command/run_script_command.rs b/crates/shirabe/src/command/run_script_command.rs
index e58ad24..9118463 100644
--- a/crates/shirabe/src/command/run_script_command.rs
+++ b/crates/shirabe/src/command/run_script_command.rs
@@ -10,6 +10,7 @@ use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputArgument;
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::script::Event as ScriptEvent;
 use crate::script::ScriptEvents;
 use crate::util::Platform;
diff --git a/crates/shirabe/src/command/search_command.rs b/crates/shirabe/src/command/search_command.rs
index 9375ec7..2033cfc 100644
--- a/crates/shirabe/src/command/search_command.rs
+++ b/crates/shirabe/src/command/search_command.rs
@@ -4,6 +4,7 @@ use crate::command::{BaseCommand, BaseCommandData, HasBaseCommandData};
 use crate::console::input::InputArgument;
 use crate::console::input::InputOption;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::plugin::CommandEvent;
 use crate::plugin::PluginEvents;
@@ -73,8 +74,8 @@ impl SearchCommand {
             c
         } else {
             // TODO(phase-b): clone_box to release self borrow held by get_io.
-            let io_box = self.get_io().clone_box();
-            self.create_composer_instance(input, io_box.as_ref(), None, false, None)?
+            let io_box = self.get_io().clone();
+            self.create_composer_instance(input, io_box, None, false, None)?
         };
         let composer_ref = crate::command::composer_full(&composer);
         // TODO(phase-b): get_local_repository returns &dyn InstalledRepositoryInterface but we need Box<dyn RepositoryInterface>
diff --git a/crates/shirabe/src/command/self_update_command.rs b/crates/shirabe/src/command/self_update_command.rs
index 80d8b01..fc22ab7 100644
--- a/crates/shirabe/src/command/self_update_command.rs
+++ b/crates/shirabe/src/command/self_update_command.rs
@@ -28,6 +28,7 @@ use crate::console::input::InputOption;
 use crate::downloader::FilesystemException;
 use crate::factory::Factory;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::self_update::Keys;
 use crate::self_update::Versions;
 use crate::util::Filesystem;
@@ -132,7 +133,7 @@ impl SelfUpdateCommand {
 
         let io = self.get_io();
         let http_downloader = std::rc::Rc::new(std::cell::RefCell::new(
-            Factory::create_http_downloader(io, &config, indexmap::IndexMap::new())?,
+            Factory::create_http_downloader(io.clone(), &config, indexmap::IndexMap::new())?,
         ));
 
         let mut versions_util = Versions::new(config.clone(), http_downloader.clone());
@@ -142,7 +143,7 @@ impl SelfUpdateCommand {
         for channel in Versions::CHANNELS {
             if input.get_option(channel).as_bool().unwrap_or(false) {
                 requested_channel = Some(channel.to_string());
-                versions_util.set_channel(channel.to_string(), Some(io))??;
+                versions_util.set_channel(channel.to_string(), Some(&*io.borrow()))??;
                 break;
             }
         }
diff --git a/crates/shirabe/src/command/show_command.rs b/crates/shirabe/src/command/show_command.rs
index c7c2f9d..f3c1b3d 100644
--- a/crates/shirabe/src/command/show_command.rs
+++ b/crates/shirabe/src/command/show_command.rs
@@ -22,6 +22,7 @@ use crate::dependency_resolver::DefaultPolicy;
 use crate::dependency_resolver::PolicyInterface;
 use crate::filter::platform_requirement_filter::PlatformRequirementFilterInterface;
 use crate::io::IOInterface;
+use crate::io::IOInterfaceImmutable;
 use crate::json::JsonFile;
 use crate::package::CompletePackageInterface;
 use crate::package::Link;
@@ -1144,7 +1145,7 @@ impl ShowCommand {
                     ),
                 );
             }
-            let io: &mut dyn IOInterface = self.get_io();
+            let io = self.get_io();
             io.write(&JsonFile::encode(
                 &PhpMixed::Array(
                     json_map
@@ -1158,7 +1159,7 @@ impl ShowCommand {
             if input.get_option("latest").as_bool() == Some(true)
                 && view_data.values().any(|v| !v.is_empty())
             {
-                let io: &mut dyn IOInterface = self.get_io();
+                let io = self.get_io();
                 if !io.is_decorated() {
                     io.write_error("Legend:");
                     io.write_error("! patch or minor release available - update recommended");
@@ -1315,7 +1316,7 @@ impl ShowCommand {
         write_release_date: bool,
         release_date_length: usize,
     ) {
-        let io: &mut dyn IOInterface = self.get_io();
+        let io = self.get_io();
         let pad_name = write_version || write_latest || write_release_date || write_description;
         let pad_version = write_latest || write_release_date || write_description;
         let pad_latest = write_description || write_release_date;
@@ -2681,7 +2682,7 @@ impl ShowCommand {
             &best_stability,
             None,
             0,
-            Some(self.get_io()),
+            Some(&*self.get_io().borrow()),
             PhpMixed::Bool(true),
         )?;
         while let Some(ref c) = candidate {
diff --git a/crates/shirabe/src/command/status_command.rs b/crates/shirabe/src/command/status_command.rs
index 69c36a1..182dec8 100644
--- a/crates/shirabe/src/command/status_command.rs
+++ b/crates/shirabe/src/command/status_command.rs
@@ -87,8 +87,9 @@ impl StatusCommand {
         let composer = self.require_composer(None, None)?;
         let mut composer = crate::command::composer_full_mut(&composer);
         // TODO(phase-b): release the &mut self borrow held by get_io via clone_box.
-        let io_box = self.get_io().clone_box();
-        let io: &dyn IOInterface = io_box.as_ref();
+        let io_box = self.get_io().clone();
+        let io_ref = io_box.borrow();
+        let io: &dyn IOInterface = &*io_ref;
 
         let mut errors: IndexMap<String, String> = IndexMap::new();
         let mut unpushed_changes: IndexMap<String, String> = IndexMap::new();
@@ -101,12 +102,16 @@ impl StatusCommand {
             .borrow()
             .get_process_executor()
             .map(std::rc::Rc::clone)
-            .unwrap_or_else(|| std::rc::Rc::new(std::cell::RefCell::new(ProcessExecutor::new(io))));
+            .unwrap_or_else(|| {
+                std::rc::Rc::new(std::cell::RefCell::new(ProcessExecutor::new(Some(
+                    io_box.clone(),
+                ))))
+            });
         let mut guesser = VersionGuesser::new(
             composer.get_config(),
             process_executor.clone(),
             parser.clone(),
-            Some(io_box.clone_box()),
+            Some(io_box.clone()),
         );
         let dumper = ArrayDumper::new();
 
diff --git a/crates/shirabe/src/command/suggests_command.rs b/crates/shirabe/src/command/suggests_command.rs
index 8166c1e..b4693a2 100644
--- a/crates/shirabe/src/command/suggests_command.rs
+++ b/crates/shirabe/src/command/suggests_command.rs
@@ -90,8 +90,9 @@ impl SuggestsCommand {
         }
 
         let installed_repo = InstalledRepository::new(installed_repos);
-        // TODO(phase-b): SuggestedPackagesReporter::new expects Box<dyn IOInterface>; self.get_io() returns &mut dyn IOInterface
-        let io_box: Box<dyn IOInterface> = todo!("share IOInterface as Box<dyn IOInterface>");
+        // TODO(phase-b): SuggestedPackagesReporter::new expects std::rc::Rc<std::cell::RefCell<dyn IOInterface>>; self.get_io() returns &mut dyn IOInterface
+        let io_box: std::rc::Rc<std::cell::RefCell<dyn IOInterface>> =
+            todo!("share IOInterface as Box<dyn IOInterface>");
         let mut reporter = SuggestedPackagesReporter::new(io_box);
 
         let filter = input.get_argument("packages");
diff --git a/crates/shirabe/src/command/update_command.rs b/crates/shirabe/src/command/update_command.rs
index 06984e2..f879283 100644
--- a/crates/shirabe/src/command/update_command.rs
+++ b/crates/shirabe/src/command/update_command.rs
@@ -77,8 +77,9 @@ impl UpdateCommand {
     ) -> Result<i64> {
         // TODO(phase-b): clone_box avoids the &mut self conflict with require_composer
         // below; revisit when get_io can return an Rc/Arc owned handle.
-        let io_box = self.get_io().clone_box();
-        let io: &dyn IOInterface = &*io_box;
+        let io_box = self.get_io().clone();
+        let io_ref = io_box.borrow();
+        let io: &dyn IOInterface = &*io_ref;
         if input.get_option("dev").as_bool().unwrap_or(false) {
             io.write_error3(
                 "<warning>You are using the deprecated option \"--dev\". It has no effect and will break in Composer 3.</warning>",
@@ -311,7 +312,7 @@ impl UpdateCommand {
             .borrow_mut()
             .set_output_progress(!input.get_option("no-progress").as_bool().unwrap_or(false));
 
-        let mut install = Installer::create(io.clone_box(), &composer_handle);
+        let mut install = Installer::create(io_box.clone(), &composer_handle);
 
         let config = composer.get_config();
         let (prefer_source, prefer_dist) =
diff --git a/crates/shirabe/src/command/validate_command.rs b/crates/shirabe/src/command/validate_command.rs
index 814f09f..cb8fa89 100644
--- a/crates/shirabe/src/command/validate_command.rs
+++ b/crates/shirabe/src/command/validate_command.rs
@@ -119,8 +119,9 @@ impl ValidateCommand {
             .map(Ok)
             .unwrap_or_else(Factory::get_composer_file)?;
         // TODO(phase-b): get_io() takes &mut self via BaseCommand; clone_box to release the borrow.
-        let io_box = self.get_io().clone_box();
-        let io: &dyn IOInterface = io_box.as_ref();
+        let io_box = self.get_io().clone();
+        let io_ref = io_box.borrow();
+        let io: &dyn IOInterface = &*io_ref;
 
         if !std::path::Path::new(&file).exists() {
             io.write_error(&format!("<error>{} not found.</error>", file));
@@ -131,7 +132,7 @@ impl ValidateCommand {
             return Ok(3);
         }
 
-        let validator = ConfigValidator::new(io.clone_box());
+        let validator = ConfigValidator::new(io_box.clone());
         let check_all = if input.get_option("no-check-all").as_bool().unwrap_or(false) {
             0
         } else {
@@ -156,7 +157,7 @@ impl ValidateCommand {
             validator.validate(&file, check_all, check_version);
 
         let mut lock_errors: Vec<String> = vec![];
-        let composer = self.create_composer_instance(input, io, None, false, None)?;
+        let composer = self.create_composer_instance(input, io_box.clone(), None, false, None)?;
         let mut composer = crate::command::composer_full_mut(&composer);
         let check_lock = (check_lock
             && composer