diff -u eglibc-2.12.1/debian/changelog eglibc-2.12.1/debian/changelog
--- eglibc-2.12.1/debian/changelog
+++ eglibc-2.12.1/debian/changelog
@@ -1,3 +1,13 @@
+eglibc (2.12.1-0ubuntu12) natty; urgency=low
+
+  * debian/debhelper.in/libc.postinst: re-add chroot check before running
+    "telinit u" as this causes a reboot under d-i (which uses busybox as
+    /sbin/init) with upstart's telinit (which sends SIGTERM to init, not
+    SIGHUP as sysvinit's telinit does); thanks Colin Watson for the analysis;
+    LP: #694772.
+
+ -- Loïc Minier <loic.minier@ubuntu.com>  Tue, 04 Jan 2011 14:10:43 +0100
+
 eglibc (2.12.1-0ubuntu11) natty; urgency=low
 
   * Update to the eglibc 2.12 branch (r12365).
diff -u eglibc-2.12.1/debian/debhelper.in/libc.postinst eglibc-2.12.1/debian/debhelper.in/libc.postinst
--- eglibc-2.12.1/debian/debhelper.in/libc.postinst
+++ eglibc-2.12.1/debian/debhelper.in/libc.postinst
@@ -240,9 +240,17 @@
 	fi # end upgrading and $preversion lt 2.12
     fi # Upgrading
 
-    # Restart init. If it fails, there is nothing we can do, so 
-    # just ignore the error
-    telinit u 2> /dev/null || true ; sleep 1
+    # try to restart init, unless in a chroot (may only be tested under Linux);
+    # the chroot test is important in the case of e.g. d-i using busybox as
+    # /sbin/init and installing upstart in a chroot: upstart's telinit sends
+    # init a SIGTERM and busybox reboots on SIGTERM
+    if [ "`uname -s`" != Linux ] || [ "$(stat -c %d/%i /)" = "$(stat -Lc %d/%i /proc/1/root 2>/dev/null)" ]; then
+        # we ignore errors because there is nothing we can do if that fails,
+        # and some weird/broken environments (e.g. no /dev/initctl but a
+        # telinit expecting one) fail to run "telinit u"
+        telinit u 2>/dev/null || true
+        sleep 1
+    fi
 fi
 
 #DEBHELPER#