sbuild::chroot: Add preserve-environment key

Move handling complete environment out of sbuild::auth;
the minimal environment and auth_environment are now only
PAM-provided environment variables.  These are merged with
the user environment only when required.

Functions using the environment for HOME and PATH now need
explicitly providing with an environment.

19 files changed, 180 insertions, 56 deletions

diff --git a/bin/dchroot-dsa/dchroot-dsa-session.cc b/bin/dchroot-dsa/dchroot-dsa-session.cc
index 8d2cc742..a872c1b9 100644
--- a/bin/dchroot-dsa/dchroot-dsa-session.cc
+++ b/bin/dchroot-dsa/dchroot-dsa-session.cc
@@ -90,7 +90,7 @@ session::get_chroot_auth_status (sbuild::auth::status status,
 }
 
 sbuild::string_list
-session::get_login_directories () const
+session::get_login_directories (sbuild::environment const& env) const
 {
   sbuild::string_list ret;
 
@@ -113,9 +113,10 @@ session::get_login_directories () const
 }
 
 void
-session::get_user_command (sbuild::chroot::ptr& session_chroot,
-			   std::string&         file,
-			   sbuild::string_list& command) const
+session::get_user_command (sbuild::chroot::ptr&       session_chroot,
+			   std::string&               file,
+			   sbuild::string_list&       command,
+			   sbuild::environment const& env) const
 {
   std::string programstring = command[0];
   file = programstring;
diff --git a/bin/dchroot-dsa/dchroot-dsa-session.h b/bin/dchroot-dsa/dchroot-dsa-session.h
index 20ad328b..abb5aeeb 100644
--- a/bin/dchroot-dsa/dchroot-dsa-session.h
+++ b/bin/dchroot-dsa/dchroot-dsa-session.h
@@ -61,12 +61,13 @@ namespace dchroot_dsa
 			    sbuild::chroot::ptr const& chroot) const;
 
     virtual sbuild::string_list
-    get_login_directories () const;
+    get_login_directories (sbuild::environment const& env) const;
 
     virtual void
-    get_user_command (sbuild::chroot::ptr& session_chroot,
-		      std::string&         file,
-		      sbuild::string_list& command) const;
+    get_user_command (sbuild::chroot::ptr&       session_chroot,
+		      std::string&               file,
+		      sbuild::string_list&       command,
+		      sbuild::environment const& env) const;
   };
 
 }
diff --git a/bin/dchroot/dchroot-session-base.cc b/bin/dchroot/dchroot-session-base.cc
index 4fe75a07..3d8ef4ed 100644
--- a/bin/dchroot/dchroot-session-base.cc
+++ b/bin/dchroot/dchroot-session-base.cc
@@ -76,9 +76,9 @@ session_base::run_impl ()
 }
 
 sbuild::string_list
-session_base::get_command_directories () const
+session_base::get_command_directories (sbuild::environment const& env) const
 {
   // dchroot does not treat logins differently from commands with
   // respect to the cwd inside the chroot.
-  return get_login_directories();
+  return get_login_directories(env);
 }
diff --git a/bin/dchroot/dchroot-session-base.h b/bin/dchroot/dchroot-session-base.h
index 1d8938f3..d6da5f4e 100644
--- a/bin/dchroot/dchroot-session-base.h
+++ b/bin/dchroot/dchroot-session-base.h
@@ -75,7 +75,7 @@ namespace dchroot
     run_impl ();
 
     virtual sbuild::string_list
-    get_command_directories () const;
+    get_command_directories (sbuild::environment const& env) const;
 
   private:
     /// dchroot compatibility enabled?
diff --git a/bin/dchroot/dchroot-session.cc b/bin/dchroot/dchroot-session.cc
index acd4710a..b25ef083 100644
--- a/bin/dchroot/dchroot-session.cc
+++ b/bin/dchroot/dchroot-session.cc
@@ -68,7 +68,7 @@ session::get_chroot_auth_status (sbuild::auth::status status,
 }
 
 sbuild::string_list
-session::get_login_directories () const
+session::get_login_directories (sbuild::environment const& env) const
 {
   sbuild::string_list ret;
 
@@ -96,9 +96,10 @@ session::get_login_directories () const
 }
 
 void
-session::get_user_command (sbuild::chroot::ptr& session_chroot,
-			   std::string&         file,
-			   sbuild::string_list& command) const
+session::get_user_command (sbuild::chroot::ptr&       session_chroot,
+			   std::string&               file,
+			   sbuild::string_list&       command,
+			   sbuild::environment const& env) const
 {
   std::string programstring = sbuild::string_list_to_string(command, " ");
 
diff --git a/bin/dchroot/dchroot-session.h b/bin/dchroot/dchroot-session.h
index 8c215c00..700eac06 100644
--- a/bin/dchroot/dchroot-session.h
+++ b/bin/dchroot/dchroot-session.h
@@ -60,12 +60,13 @@ namespace dchroot
 			    sbuild::chroot::ptr const& chroot) const;
 
     virtual sbuild::string_list
-    get_login_directories () const;
+    get_login_directories (sbuild::environment const& env) const;
 
     virtual void
-    get_user_command (sbuild::chroot::ptr& session_chroot,
-		      std::string&         file,
-		      sbuild::string_list& command) const;
+    get_user_command (sbuild::chroot::ptr&       session_chroot,
+		      std::string&               file,
+		      sbuild::string_list&       command,
+		      sbuild::environment const& env) const;
   };
 
 }
diff --git a/bin/schroot/schroot-main-base.cc b/bin/schroot/schroot-main-base.cc
index 81927f88..f1a8dac2 100644
--- a/bin/schroot/schroot-main-base.cc
+++ b/bin/schroot/schroot-main-base.cc
@@ -301,8 +301,7 @@ main_base::run_impl ()
 	this->session->get_auth()->set_command(this->options->command);
       if (!this->options->directory.empty())
 	this->session->get_auth()->set_wd(this->options->directory);
-      if (this->options->preserve)
-	this->session->get_auth()->set_environment(environ);
+      this->session->set_preserve_environment(this->options->preserve);
       this->session->set_session_id(this->options->session_name);
       this->session->set_force(this->options->session_force);
       if (this->options->quiet)
diff --git a/man/schroot.1.in b/man/schroot.1.in
index f463990c..6831fc5b 100644
--- a/man/schroot.1.in
+++ b/man/schroot.1.in
@@ -157,7 +157,7 @@ status.
 .IP
 The default behaviour is as follows (all directory paths are inside the
 chroot).  A login shell is run in the current working directory.  If this is
-not available, it will try $HOME (when \fI\\-\-preserve\-environment\fP is
+not available, it will try $HOME (when \fI\-\-preserve\-environment\fP is
 used), then the user's home directory, and \fI/\fP inside the chroot in turn.
 A command is always run in the current working directory inside the chroot.  If
 none of the directories are available, schroot will exit with an error status.
diff --git a/man/schroot.conf.5.in b/man/schroot.conf.5.in
index a68760be..46f12b83 100644
--- a/man/schroot.conf.5.in
+++ b/man/schroot.conf.5.in
@@ -130,7 +130,14 @@ Linux are \[oq]bsd\[cq], \[oq]hpux\[cq], \[oq]irix32\[cq], \[oq]irix64\[cq],
 systems is \[oq]undefined\[cq].  The default value for non-Linux systems is
 \[oq]undefined\[cq].
 .TP
-\f[CBI]environment\-filter=\fP\f[CI]refex\fP
+\f[CBI]preserve\-environment=\fP\f[CI]true\fP|\f[CI]false\fP
+By default, the environment will not be preserved inside the chroot, instead a
+minimal environment will be used.  Set to \f[CI]true\fP to always preserve the
+environment.  This is useful for example when running X applications inside the
+chroot, which need the environment to function correctly.  The environment may
+also be preserved using the \fI\-\-preserve\-environment\fP option.
+.TP
+\f[CBI]environment\-filter=\fP\f[CI]regex\fP
 The environment to be set in the chroot will be filtered in order to remove
 environment variables which may pose a security risk.  Any environment variable
 matching the specified POSIX extended regular expression will be removed prior
diff --git a/sbuild/sbuild-auth.cc b/sbuild/sbuild-auth.cc
index ed156a8d..86b2ab18 100644
--- a/sbuild/sbuild-auth.cc
+++ b/sbuild/sbuild-auth.cc
@@ -29,6 +29,7 @@
 #include <sstream>
 
 #include <syslog.h>
+#include <unistd.h>
 
 #include <boost/format.hpp>
 
@@ -77,7 +78,7 @@ auth::auth (std::string const& service_name):
   home(),
   wd(),
   shell(),
-  user_environment(),
+  user_environment(environ),
   ruid(),
   rgid(),
   ruser(),
@@ -231,8 +232,6 @@ environment
 auth::get_minimal_environment () const
 {
   environment minimal;
-  if (!this->user_environment.empty())
-    minimal = this->user_environment;
 
   // For security, PATH is always set to a sane state for root, but
   // only set in other cases if not preserving the environment.
@@ -264,6 +263,12 @@ auth::get_minimal_environment () const
   return minimal;
 }
 
+environment
+auth::get_complete_environment () const
+{
+  return get_auth_environment() + get_environment();
+}
+
 uid_t
 auth::get_ruid () const
 {
diff --git a/sbuild/sbuild-auth.h b/sbuild/sbuild-auth.h
index 83cb270e..0986d57e 100644
--- a/sbuild/sbuild-auth.h
+++ b/sbuild/sbuild-auth.h
@@ -245,14 +245,23 @@ namespace sbuild
     set_environment (environment const& environment);
 
     /**
-     * Get the minimal environment.  This is the user environment plus
+     * Get the minimal environment.  This is essential environment
+     * variables which are set if not already present.
+     *
+     * @returns an environment list.
+     */
+    environment
+    get_minimal_environment () const;
+
+    /**
+     * Get the complete environment.  This is the user environment plus
      * essential environment variables which are set if not already
      * present.
      *
      * @returns an environment list.
      */
     environment
-    get_minimal_environment () const;
+    get_complete_environment () const;
 
     /**
      * Get the PAM environment.  This is the environment as set by PAM
diff --git a/sbuild/sbuild-chroot.cc b/sbuild/sbuild-chroot.cc
index 37ef6fa0..c048639e 100644
--- a/sbuild/sbuild-chroot.cc
+++ b/sbuild/sbuild-chroot.cc
@@ -108,6 +108,7 @@ sbuild::chroot::chroot ():
   root_users(),
   root_groups(),
   aliases(),
+  preserve_environment(false),
   environment_filter(SBUILD_DEFAULT_ENVIRONMENT_FILTER),
   mount_location(),
   original(true),
@@ -131,6 +132,7 @@ sbuild::chroot::chroot (const chroot& rhs):
   root_users(rhs.root_users),
   root_groups(rhs.root_groups),
   aliases(rhs.aliases),
+  preserve_environment(rhs.preserve_environment),
   environment_filter(rhs.environment_filter),
   mount_location(rhs.mount_location),
   original(rhs.original),
@@ -324,6 +326,18 @@ sbuild::chroot::set_aliases (string_list const& aliases)
   this->aliases = aliases;
 }
 
+bool
+sbuild::chroot::get_preserve_environment () const
+{
+  return this->preserve_environment;
+}
+
+void
+sbuild::chroot::set_preserve_environment (bool preserve_environment)
+{
+  this->preserve_environment = preserve_environment;
+}
+
 regex const&
 sbuild::chroot::get_environment_filter () const
 {
@@ -596,6 +610,7 @@ sbuild::chroot::get_details (chroot const&  chroot,
     .add(_("Root Users"), chroot.get_root_users())
     .add(_("Root Groups"), chroot.get_root_groups())
     .add(_("Aliases"), chroot.get_aliases())
+    .add(_("Preserve Environment"), chroot.get_preserve_environment())
     .add(_("Environment Filter"), chroot.get_environment_filter())
     .add(_("Run Setup Scripts"), chroot.get_run_setup_scripts())
     .add(_("Script Configuration"), chroot.get_script_config())
@@ -703,6 +718,10 @@ sbuild::chroot::get_keyfile (chroot const& chroot,
   keyfile::set_object_value(chroot, &chroot::get_verbosity_string,
 			    keyfile, chroot.get_keyfile_name(),
 			    "message-verbosity");
+
+  keyfile::set_object_value(chroot, &chroot::get_preserve_environment,
+			    keyfile, chroot.get_keyfile_name(),
+			    "preserve-environment");
 }
 
 void
@@ -849,4 +868,10 @@ sbuild::chroot::set_keyfile (chroot&        chroot,
 			    "message-verbosity",
 			    keyfile::PRIORITY_OPTIONAL);
   used_keys.push_back("message-verbosity");
+
+  keyfile::get_object_value(chroot, &chroot::set_preserve_environment,
+			    keyfile, chroot.get_keyfile_name(),
+			    "preserve-environment",
+			    keyfile::PRIORITY_OPTIONAL);
+  used_keys.push_back("preserve-environment");
 }
diff --git a/sbuild/sbuild-chroot.h b/sbuild/sbuild-chroot.h
index 2788bbde..03fac5d0 100644
--- a/sbuild/sbuild-chroot.h
+++ b/sbuild/sbuild-chroot.h
@@ -352,6 +352,22 @@ namespace sbuild
     set_aliases (string_list const& aliases);
 
     /**
+     * Check if the environment should be preserved in the chroot.
+     *
+     * @returns true to preserve or false to clean.
+     */
+    bool
+    get_preserve_environment () const;
+
+    /**
+     * Set if the environment should be preserved in the chroot.
+     *
+     * @param preserve_environment true to preserve or false to clean.
+     */
+    void
+    set_preserve_environment (bool preserve_environment);
+
+    /**
      * Get the environment filter of the chroot.  This is a POSIX
      * extended regular expression used to remove insecure environment
      * variables from the chroot environment.
@@ -362,7 +378,7 @@ namespace sbuild
     get_environment_filter () const;
 
     /**
-     * Get the environment filter of the chroot.  This is a POSIX
+     * Set the environment filter of the chroot.  This is a POSIX
      * extended regular expression used to remove insecure environment
      * variables from the chroot environment.
      *
@@ -760,6 +776,8 @@ namespace sbuild
     string_list   root_groups;
     /// Alternative names for the chroot.
     string_list   aliases;
+    /// Preserve environment?
+    bool          preserve_environment;
     /// Environment filter regex.
     regex         environment_filter;
     /// Location to mount chroot in the filesystem (if any).
diff --git a/sbuild/sbuild-session.cc b/sbuild/sbuild-session.cc
index cac37cc3..24a4183b 100644
--- a/sbuild/sbuild-session.cc
+++ b/sbuild/sbuild-session.cc
@@ -272,6 +272,7 @@ session::session (std::string const&         service,
   saved_termios(),
   termios_ok(false),
   verbosity(),
+  preserve_environment(false),
   cwd(sbuild::getcwd())
 {
 }
@@ -353,6 +354,18 @@ session::set_verbosity (std::string const& verbosity)
 }
 
 bool
+session::get_preserve_environment () const
+{
+  return this->preserve_environment;
+}
+
+void
+session::set_preserve_environment (bool preserve_environment)
+{
+  this->preserve_environment = preserve_environment;
+}
+
+bool
 session::get_force () const
 {
   return this->force;
@@ -632,10 +645,6 @@ session::run_impl ()
 	  chroot::ptr chroot(ch->clone());
 	  assert(chroot);
 
-	  // Override chroot verbosity if needed.
-	  if (!this->verbosity.empty())
-	    ch->set_verbosity(this->verbosity);
-
 	  /* Create a session using randomly-generated session ID. */
 	  if (ch->get_session_flags() & chroot::SESSION_CREATE)
 	    {
@@ -676,6 +685,10 @@ session::run_impl ()
 	    }
 	  assert(chroot);
 
+	  // Override chroot verbosity if needed.
+	  if (!this->verbosity.empty())
+	    chroot->set_verbosity(this->verbosity);
+
 	  // Following authentication success, default child status to
 	  // success so that operations such as beginning, ending and
 	  // recovering sessions will return success unless an
@@ -756,7 +769,7 @@ session::run_impl ()
 }
 
 string_list
-session::get_login_directories () const
+session::get_login_directories (environment const& env) const
 {
   string_list ret;
 
@@ -772,7 +785,6 @@ session::get_login_directories () const
       ret.push_back(this->cwd);
 
       // Set $HOME.
-      environment env = this->authstat->get_auth_environment();
       std::string home;
       if (env.get("HOME", home) &&
 	  std::find(ret.begin(), ret.end(), home) == ret.end())
@@ -791,7 +803,7 @@ session::get_login_directories () const
 }
 
 string_list
-session::get_command_directories () const
+session::get_command_directories (environment const& env) const
 {
   string_list ret;
 
@@ -835,14 +847,15 @@ session::get_shell () const
 void
 session::get_command (sbuild::chroot::ptr& session_chroot,
 		      std::string&         file,
-		      string_list&         command) const
+		      string_list&         command,
+		      environment const&   env) const
 {
   /* Run login shell */
   if (command.empty() ||
       command[0].empty()) // No command
     get_login_command(session_chroot, file, command);
   else
-    get_user_command(session_chroot, file, command);
+    get_user_command(session_chroot, file, command, env);
 }
 
 void
@@ -930,10 +943,10 @@ session::get_login_command (sbuild::chroot::ptr& session_chroot,
 void
 session::get_user_command (sbuild::chroot::ptr& session_chroot,
 			   std::string&         file,
-			   string_list&         command) const
+			   string_list&         command,
+			   environment const&   env) const
 {
   /* Search for program in path. */
-  environment env = this->authstat->get_auth_environment();
   std::string path;
   if (!env.get("PATH", path))
     path.clear();
@@ -1148,6 +1161,15 @@ session::run_child (sbuild::chroot::ptr& session_chroot)
   assert(!get_shell().empty());
   assert(this->authstat->is_initialised()); // PAM must be initialised
 
+  /* Set up environment */
+  environment env;
+  env.set_filter(session_chroot->get_environment_filter());
+
+  if (get_preserve_environment() || session_chroot->get_preserve_environment())
+    env += this->authstat->get_complete_environment();
+  else
+    env += this->authstat->get_auth_environment();
+
   // Store before chroot call.
   this->cwd = sbuild::getcwd();
   log_debug(DEBUG_INFO) << "CWD=" << this->cwd << std::endl;
@@ -1201,9 +1223,9 @@ session::run_child (sbuild::chroot::ptr& session_chroot)
   string_list dlist;
   if (command.empty() ||
       command[0].empty()) // No command
-    dlist = get_login_directories();
+    dlist = get_login_directories(env);
   else
-    dlist = get_command_directories();
+    dlist = get_command_directories(env);
   log_debug(DEBUG_INFO)
     << format("Directory fallbacks: %1%") % string_list_to_string(dlist, ", ") << endl;
 
@@ -1235,16 +1257,11 @@ session::run_child (sbuild::chroot::ptr& session_chroot)
     }
 
   /* Fix up the command for exec. */
-  get_command(session_chroot, file, command);
+  get_command(session_chroot, file, command, env);
   log_debug(DEBUG_NOTICE) << "command="
 			  << string_list_to_string(command, ", ")
 			  << std::endl;
 
-  /* Set up environment */
-  environment env;
-  env.set_filter(session_chroot->get_environment_filter());
-  env += this->authstat->get_auth_environment();
-
   // Add equivalents to sudo's SUDO_USER, SUDO_UID, SUDO_GID, and
   // SUDO_COMMAND.
   env.add(std::make_pair("SCHROOT_COMMAND",
diff --git a/sbuild/sbuild-session.h b/sbuild/sbuild-session.h
index e7c79bed..fe74e162 100644
--- a/sbuild/sbuild-session.h
+++ b/sbuild/sbuild-session.h
@@ -215,6 +215,22 @@ namespace sbuild
     set_verbosity (std::string const& verbosity);
 
     /**
+     * Check if the environment should be preserved in the chroot.
+     *
+     * @returns true to preserve or false to clean.
+     */
+    bool
+    get_preserve_environment () const;
+
+    /**
+     * Set if the environment should be preserved in the chroot.
+     *
+     * @param preserve_environment true to preserve or false to clean.
+     */
+    void
+    set_preserve_environment (bool preserve_environment);
+
+    /**
      * Get the force status of this session.
      *
      * @returns true if operation will be forced, otherwise false.
@@ -304,19 +320,21 @@ namespace sbuild
      * Get a list of directories to change to when running a login
      * shell.  Multiple directories are used as fallbacks.
      *
+     * @param env the environment to use for HOME
      * @returns a list of directories
      */
     virtual string_list
-    get_login_directories () const;
+    get_login_directories (environment const& env) const;
 
     /**
      * Get a list of directories to change to when running a command
      * Multiple directories are used as fallbacks.
      *
+     * @param env the environment to use for HOME
      * @returns a list of directories
      */
     virtual string_list
-    get_command_directories () const;
+    get_command_directories (environment const& env) const;
 
     /**
      * Get the shell to run.  This finds a suitable shell to run in
@@ -335,11 +353,13 @@ namespace sbuild
      * present in the chroot list and the chroot configuration object.
      * @param file the filename to pass to execve(2).
      * @param command the argv to pass to execve(2).
+     * @param env the environment to use for PATH
      */
     virtual void
-    get_command (chroot::ptr& session_chroot,
-		 std::string& file,
-		 string_list& command) const;
+    get_command (chroot::ptr&       session_chroot,
+		 std::string&       file,
+		 string_list&       command,
+		 environment const& env) const;
 
     /**
      * Get the command to run a login shell.
@@ -361,11 +381,13 @@ namespace sbuild
      * present in the chroot list and the chroot configuration object.
      * @param file the filename to pass to execve(2).
      * @param command the argv to pass to execve(2).
+     * @param env the environment to use for PATH
      */
     virtual void
-    get_user_command (chroot::ptr& session_chroot,
-		      std::string& file,
-		      string_list& command) const;
+    get_user_command (chroot::ptr&       session_chroot,
+		      std::string&       file,
+		      string_list&       command,
+		      environment const& env) const;
 
   private:
     /**
@@ -515,6 +537,8 @@ namespace sbuild
     bool termios_ok;
     /// Message verbosity.
     std::string verbosity;
+    /// Preserve environment?
+    bool        preserve_environment;
 
   protected:
     /// Current working directory.
diff --git a/test/config.ex2/sarge b/test/config.ex2/sarge
index 359ce713..8306da10 100644
--- a/test/config.ex2/sarge
+++ b/test/config.ex2/sarge
@@ -6,3 +6,4 @@ groups=sbuild
 root-groups=root,sbuild
 #root-groups=root
 aliases=stable
+preserve-environment=true
\ No newline at end of file
diff --git a/test/config.ex2/sid b/test/config.ex2/sid
index 03d271ca..fdd25a30 100644
--- a/test/config.ex2/sid
+++ b/test/config.ex2/sid
@@ -16,3 +16,4 @@ groups=sbuild,root
 root-groups=root,sbuild
 directory=/srv/chroot/sid
 message-verbosity=verbose
+preserve-environment=false
\ No newline at end of file
diff --git a/test/sbuild-chroot.cc b/test/sbuild-chroot.cc
index 850a7aa0..fda58514 100644
--- a/test/sbuild-chroot.cc
+++ b/test/sbuild-chroot.cc
@@ -115,6 +115,7 @@ class test_chroot : public test_chroot_base<basic_chroot>
   CPPUNIT_TEST(test_active);
   CPPUNIT_TEST(test_run_setup_scripts);
   CPPUNIT_TEST(test_verbose);
+  CPPUNIT_TEST(test_preserve_environment);
   CPPUNIT_TEST_EXCEPTION(test_verbose_error, sbuild::chroot::error);
   CPPUNIT_TEST(test_chroot_type);
   CPPUNIT_TEST(test_setup_env);
@@ -231,6 +232,17 @@ public:
     CPPUNIT_ASSERT(std::string(chroot->get_verbosity_string()) == "normal");
   }
 
+  void test_preserve_environment()
+  {
+    std::tr1::shared_ptr<basic_chroot> c = std::tr1::dynamic_pointer_cast<basic_chroot>(chroot);
+
+    CPPUNIT_ASSERT(chroot->get_preserve_environment() == false);
+    c->set_preserve_environment(true);
+    CPPUNIT_ASSERT(chroot->get_preserve_environment() == true);
+    c->set_preserve_environment(false);
+    CPPUNIT_ASSERT(chroot->get_preserve_environment() == false);
+  }
+
   void test_verbose_error()
   {
     std::tr1::shared_ptr<basic_chroot> c = std::tr1::dynamic_pointer_cast<basic_chroot>(chroot);
diff --git a/test/test-sbuild-chroot.h b/test/test-sbuild-chroot.h
index 99f95892..47b67138 100644
--- a/test/test-sbuild-chroot.h
+++ b/test/test-sbuild-chroot.h
@@ -150,6 +150,7 @@ public:
     chroot->set_groups(sbuild::split_string("group1,group2", ","));
     chroot->set_root_groups(sbuild::split_string("group3,group4", ","));
     chroot->set_verbosity("quiet");
+    chroot->set_preserve_environment(false);
 
     sbuild::chroot_facet_personality::ptr pfac
       (chroot->get_facet<sbuild::chroot_facet_personality>());
@@ -195,6 +196,7 @@ public:
     keyfile.set_value(group, "command-prefix", "");
     keyfile.set_value(group, "script-config", "default/config");
     keyfile.set_value(group, "message-verbosity", "quiet");
+    keyfile.set_value(group, "preserve-environment", "false");
   }
 
   void setup_keyfile_session (sbuild::keyfile&   keyfile,