[gnome-builder] rustup: run rustup on the host system

[Christian Hergert <chergert src gnome org>]

commit 7bcaa0f631d1e71f7b9facaa0c83cfaf5f26dec0
Author: Christian Hergert <chergert redhat com>
Date:   Sun Mar 19 14:54:42 2017 -0700

    rustup: run rustup on the host system
    
    We do all our rust toolchain management on the host, which means that we
    don't have access to the rust toolchain inside the flatpak application
    mount namespace. So ensure we run that on the host too using the bash
    trick "bash -- /dev/stdin arguments" style and writing the script to
    stdin.

 plugins/rustup/rustup_plugin/__init__.py |   32 +++++++++++++++++++----------
 1 files changed, 21 insertions(+), 11 deletions(-)
---
diff --git a/plugins/rustup/rustup_plugin/__init__.py b/plugins/rustup/rustup_plugin/__init__.py
index 70c3a01..f131a0e 100644
--- a/plugins/rustup/rustup_plugin/__init__.py
+++ b/plugins/rustup/rustup_plugin/__init__.py
@@ -289,20 +289,27 @@ class RustupInstaller(Ide.Transfer):
 
         task = Gio.Task.new(self, cancellable, callback)
 
-        launcher = Ide.SubprocessLauncher()
-        launcher.set_run_on_host(False)
+        launcher = Ide.SubprocessLauncher.new(Gio.SubprocessFlags.STDIN_PIPE)
         launcher.set_clear_env(False)
+        launcher.set_run_on_host(True)
+
+        stdin_data = None
 
         if self.mode == _MODE_INSTALL:
-            rustup_sh_path = get_module_data_path('resources/rustup.sh')
-            # XXX: ensure that the script is executable
-            #      this should not be neccessary now that we bundle rustup.sh
-            #      and its likely the script is read-only anyway.
-            # st = os.stat(rustup_sh_path)
-            # os.chmod(rustup_sh_path, st.st_mode | stat.S_IEXEC)
-            launcher.push_argv(rustup_sh_path)
-            # install default toolchain automatically
+            # Because our script is inside the application mount namespace, and we
+            # need to execute this on the host (via the subprocess helper), we need
+            # to execute it using bash and reading from stdin.
+
+            launcher.push_argv('bash')
+            launcher.push_argv('--')
+            launcher.push_argv('/dev/stdin')
             launcher.push_argv('-y')
+
+            try:
+                rustup_sh_path = get_module_data_path('resources/rustup.sh')
+                success, stdin_data = GLib.file_get_contents(rustup_sh_path)
+            except:
+                stdin_data = ""
         elif self.mode == _MODE_UPDATE:
             launcher.push_argv(RustupApplicationAddin.instance.rustup_executable)
             launcher.push_argv('update')
@@ -314,7 +321,6 @@ class RustupInstaller(Ide.Transfer):
 
         # rustup needs a tty to give us a progress bar
         (master_fd, slave_fd) = pty.openpty()
-        launcher.take_stdin_fd(os.dup(slave_fd))
         launcher.take_stdout_fd(os.dup(slave_fd))
         launcher.take_stderr_fd(slave_fd)
 
@@ -325,6 +331,10 @@ class RustupInstaller(Ide.Transfer):
 
         try:
             sub_process = launcher.spawn()
+            stdin_stream = sub_process.get_stdin_pipe()
+            if stdin_data is not None:
+                stdin_stream.write_all(stdin_data)
+            stdin_stream.close()
             sub_process.wait_async(cancellable, self._wait_cb, task)
         except Exception as ex:
             task.return_error(GLib.Error(message=repr(ex)))