libvirt-lxc: virFileOpenTtyAt can't be called on /some/other/dev/pts

The proposed fix - short of fixing glibc - is to set up an environment for the grantpt call with the container's /dev/pts bind-mounted to /dev/pts.

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I now know how I I was hitting this.
On my local system, I would log, open a terminal and and then run a bip proxy with:
 ssh -o ControlPath=none -C -L 7778:localhost:7778 -f -N ${HOST}

I can replicate that same behavior by ssh'ing to a system, then doing:
  sleep 30m & disown; exit
After that, 'sleep 30m' will be alive and holding the /dev/pts/0 so nothing will get that any more, but the entry is deleted.

I couldn't seem to get that to work through ssh running the command ie, the following kills the sleep and frees the /dev/pts/0:
  ssh $HOST -t 'sleep 30m & disown; exit 0;'

Thanks, Scott. I can now finally reproduce this :) I see you were right on irc, my debdiff does not suffice. fascinating.

Just for reference, Serge posted to libc-alpha mailing list at http://www.cygwin.com/ml/libc-alpha/2011-10/threads.html#00009 ("multiple devpts mounts not supported insysdeps/unix/sysv/linux/ptsname.c:_ptsname_internal()")

This debdiff works for me even after making /dev/pts/0 unavailable (using Scott's great 'sleep 2h & disown; exit' trick on /dev/pts/0).

I am going to upload libvirt to precise with this fix (which also tests fine on my systems). Upstream has indicated it will prefer this simpler approach.

This bug was fixed in the package libvirt - 0.9.2-4ubuntu16

---------------
libvirt (0.9.2-4ubuntu16) precise; urgency=low

  * lxc_controller: use our own unlocpt+grantpt rather than glibc's, which
    can't handle opening a pty in a devpts not mounted at /dev/pts.
    (LP: #863629)
 -- Serge Hallyn <email address hidden> Fri, 14 Oct 2011 10:47:57 -0500

Hello Serge, or anyone else affected,

Accepted libvirt into oneiric-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

Tested, works.

Nothing here to sponsor, removing ubuntu-sponsors.

This bug was fixed in the package libvirt - 0.9.2-4ubuntu15.1

---------------
libvirt (0.9.2-4ubuntu15.1) oneiric-proposed; urgency=low

  * lxc_controller: use our own unlocpt+grantpt rather than glibc's, which
    can't handle opening a pty in a devpts not mounted at /dev/pts.
    (LP: #863629)
 -- Serge Hallyn <email address hidden> Tue, 01 Nov 2011 17:52:53 +0000

Hello Serge, or anyone else affected,

Accepted libvirt into lucid-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

Failed to build for lucid:

gcc -DHAVE_CONFIG_H -I. -I.. -I../gnulib/lib -I../gnulib/lib -I../include -I../src/util -I../include -I/usr/include/libxml2 -DLIBDIR=\""/usr/lib"\" -DBINDIR=\""/usr/lib/libvirt"\" -DSBINDIR=\""/usr/sbin"\" -DSYSCONF_DIR="\"/etc\"" -DLOCALEBASEDIR=\""/usr/share/locale"\" -DPKGDATADIR=\""/usr/share/libvirt"\" -DLOCAL_STATE_DIR=\""/var"\" -DGETTEXT_PACKAGE=\"libvirt\" -Wall -Wformat -Wformat-security -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wextra -Wshadow -Wcast-align -Wwrite-strings -Waggregate-return -Wstrict-prototypes -Winline -Wredundant-decls -Wno-sign-compare -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fasynchronous-unwind-tables -I../src/conf -g -O2 -g -Wall -O2 -c -o libvirt_lxc-lxc_controller.o `test -f 'lxc/lxc_controller.c' || echo './'`lxc/lxc_controller.c
lxc/lxc_controller.c: In function 'lxcCreateTty':
lxc/lxc_controller.c:524: error: expected expression before ')' token
lxc/lxc_controller.c:533: warning: implicit declaration of function 'VIR_FORCE_CLOSE'
lxc/lxc_controller.c:533: warning: nested extern declaration of 'VIR_FORCE_CLOSE'

Sorry. Given that (a) you need a backport kernel to use lxc on lucid, and (b) this race is hard to run into anyway, I'm going to mark this wontfix for lucid. If anyone actually is bothered by this on lucid, I'm open to changing my mind, but if we can't straightforwardly backport the fix, then I'd rather not risk a regression by finagling it.

(Change of mind or heart; will upload an updated package)

Accepted 0.7.5-5ubuntu27.19 into lucid-proposed.

Hello Serge, or anyone else affected,

Accepted libvirt into maverick-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

Hello Serge, or anyone else affected,

Accepted libvirt into natty-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

Fix verified on lucid.

Hello Serge, or anyone else affected,

Accepted libvirt into maverick-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you in advance!

Verified on maverick.

Verified on natty, thanks.

This bug was fixed in the package libvirt - 0.7.5-5ubuntu27.19

---------------
libvirt (0.7.5-5ubuntu27.19) lucid-proposed; urgency=low

  * New version of debian/patches/lxc-use-own-ptyfns.patch. Previous version
    failed to build.

libvirt (0.7.5-5ubuntu27.18) lucid-proposed; urgency=low

  * lxc_controller: use our own unlocpt+grantpt rather than glibc's, which
    can't handle opening a pty in a devpts not mounted at /dev/pts.
    (LP: #863629)
 -- Serge Hallyn <email address hidden> Mon, 14 Nov 2011 15:11:24 -0600

This bug was fixed in the package libvirt - 0.8.3-1ubuntu19.4

---------------
libvirt (0.8.3-1ubuntu19.4) maverick-proposed; urgency=low

  * New version of debian/patches/lxc-use-own-ptyfns.patch. Previous version
    failed to build.

libvirt (0.8.3-1ubuntu19.3) maverick-proposed; urgency=low

  * lxc_controller: use our own unlocpt+grantpt rather than glibc's, which
    can't handle opening a pty in a devpts not mounted at /dev/pts.
    (LP: #863629)
 -- Serge Hallyn <email address hidden> Tue, 15 Nov 2011 08:06:57 -0600

This bug was fixed in the package libvirt - 0.8.8-1ubuntu6.7

---------------
libvirt (0.8.8-1ubuntu6.7) natty-proposed; urgency=low

  * lxc_controller: use our own unlocpt+grantpt rather than glibc's, which
    can't handle opening a pty in a devpts not mounted at /dev/pts.
    (LP: #863629)
 -- Serge Hallyn <email address hidden> Tue, 01 Nov 2011 18:00:51 +0000