[gnome-ostree] build: Work around lack of --mount-rbind by copying triggers inside root

[Colin Walters <walters src gnome org>]

commit 788ebd4f90d3fbde0603563e20a5e767c1feba1b
Author: Colin Walters <walters verbum org>
Date:   Tue Jul 9 22:19:53 2013 -0400

    build: Work around lack of --mount-rbind by copying triggers inside root
    
    On build.gnome.org, /srv/ostree is a mountpoint, and --mount-bind /
    /sysroot won't give us /sysroot/srv/ostree.  Hack around this here.

 src/js/tasks/task-build.js |   20 ++++++++++++++++++--
 1 files changed, 18 insertions(+), 2 deletions(-)
---
diff --git a/src/js/tasks/task-build.js b/src/js/tasks/task-build.js
index ea0f4bf..b024063 100644
--- a/src/js/tasks/task-build.js
+++ b/src/js/tasks/task-build.js
@@ -814,13 +814,27 @@ const TaskBuild = new Lang.Class({
     _runTriggersInRoot: function(rootdir, cancellable) {
        let triggersScriptPath = this.libdir.resolve_relative_path('gnome-ostree-run-triggers');
        let triggersPath = this.libdir.resolve_relative_path('triggers');
+       
+       // FIXME copy the triggers into the root temporarily; it'd be
+       // better to add --mount-rbind to linux-user-chroot so we pick
+       // up all the host mount points, and thus know we can find
+       // data from outside the root.
+       let tmpTriggersInRootPath = rootdir.get_child('tmp-triggers');
+       GSystem.file_ensure_directory(tmpTriggersInRootPath, false, cancellable);
+       let tmpTriggersScriptPath = tmpTriggersInRootPath.get_child(triggersScriptPath.get_basename());
+       let tmpTriggersPath = tmpTriggersInRootPath.get_child(triggersPath.get_basename());
+
+       triggersScriptPath.copy(tmpTriggersScriptPath, Gio.FileCopyFlags.OVERWRITE, cancellable,
+                               null);
+       GSystem.shutil_cp_a(triggersPath, tmpTriggersPath, cancellable);
+
        let childArgs = BuildUtil.getBaseUserChrootArgs();
         childArgs.push.apply(childArgs, [
            '--mount-bind', '/', '/sysroot',
             '--mount-proc', '/proc', 
             '--mount-bind', '/dev', '/dev',
-            rootdir.get_path(), '/sysroot' + triggersScriptPath.get_path(),
-           '/sysroot' + triggersPath.get_path()]);
+            rootdir.get_path(), rootdir.get_relative_path(tmpTriggersScriptPath),
+           rootdir.get_relative_path(tmpTriggersPath)]);
        let envCopy = {};
        Lang.copyProperties(BuildUtil.BUILD_ENV, envCopy);
         envCopy['PWD'] = '/';
@@ -836,6 +850,8 @@ const TaskBuild = new Lang.Class({
            print("Trigger execution in root " + rootdir.get_path() + " failed");
            throw e;
        }
+
+       GSystem.shutil_rm_rf(tmpTriggersInRootPath, cancellable);
     },
 
     _postComposeTransform: function(composeRootdir, cancellable) {