Greetings,

This morning, all of the sudden, I'm encountering process creation
problems. The problems seem to affect only bash. There are no problems
starting X applications like firefox and open office.

FWIW, my usual "update world" was done yesterday (and emerged the
packages listed at the end of this message).

Anybody have suggestions regarding the symptoms given below?

Regards,

David

### symptoms ###

Attempting to start a new terminal session from an existing terminal
session (using ctrl-shft-N).

There was an error creating the child process for this terminal

and a terminal window without a prompt (not running bash??) The same
message and window appear when I try to start one from the GNOME menu.

From emacs, running the shell command produces the following message
(and a usable shell window):

bash: cannot set terminal process group (-1): Invalid argument
bash: no job control in this shell

ssh into box gives:

PTY allocation request failed on channel 0

Neither dmesg nor /var/log/messages has any unusual messages


### recently emerged packages ###

app-crypt/gnupg-2.0.14
app-text/poppler-0.12.3-r3
dev-libs/libgcrypt-1.4.5
dev-util/global-5.7.7
media-libs/alsa-lib-1.0.21a
media-sound/alsa-headers-1.0.21
media-sound/alsa-utils-1.0.21-r1
sys-apps/util-linux-2.16.2
virtual/poppler-0.12.3-r1
virtual/poppler-glib-0.12.3-r2
virtual/poppler-utils-0.12.3-r1

Stabbing in the dark here: I don't think this is a bash problem. Most
likely something else broke on your system.

On Sat, Feb 06, 2010 at 08:33:44AM -0500, David Relson wrote:
> ssh into box gives:
>
> PTY allocation request failed on channel 0

Issue 'ls /dev/pt*' for me?

> ### recently emerged packages ###

How complete is this list? I assume you didn't reboot recently into a
new kernel? Did you upgrade udev by any chance? The only other suspect
that I see is util-linux, but you are on the stable version.
>
> app-crypt/gnupg-2.0.14
> app-text/poppler-0.12.3-r3
> dev-libs/libgcrypt-1.4.5
> dev-util/global-5.7.7
> media-libs/alsa-lib-1.0.21a
> media-sound/alsa-headers-1.0.21
> media-sound/alsa-utils-1.0.21-r1
> sys-apps/util-linux-2.16.2
> virtual/poppler-0.12.3-r1
> virtual/poppler-glib-0.12.3-r2
> virtual/poppler-utils-0.12.3-r1

Cheers,

W

--
Willie W. Wong wwong@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton

On Sat, Feb 06, 2010 at 08:33:44AM -0500, David Relson wrote:
> This morning, all of the sudden, I'm encountering process creation
> problems. The problems seem to affect only bash. There are no problems
> starting X applications like firefox and open office.

Also, can you log-in on a vc? If you are in X, hit ctrl-alt-f2 and try
to log into the console?

W
--
Willie W. Wong wwong@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton

On Sat, Feb 06, 2010 at 10:00:33AM -0500, Willie Wong wrote:
> How complete is this list? I assume you didn't reboot recently into a
> new kernel?

Also, if you did reboot recently (maybe into the same kernel), cat
/etc/fstab for me?

W
--
Willie W. Wong wwong@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton

H'lo Willie,

The output of "ls /dev/pt*" is suspiciously short:

root@osage / # ls /dev/pts
/dev/ptmx

/dev/pts:

udev was emerged twice quite recently:
1/26 upgrade from 141-r1 to 146-r2
1/32 downgrade from 146-r2 to 146-r1

My computer was last rebooted 21 days ago.

As you seem to suspect udev and /dev/pt* seems b0rked, I'll try
downgrading back to 141-r1 to see what happens.

Regards,

David


On Sat, 6 Feb 2010 10:00:33 -0500
Willie Wong wrote:

> Stabbing in the dark here: I don't think this is a bash problem. Most
> likely something else broke on your system.
>
> On Sat, Feb 06, 2010 at 08:33:44AM -0500, David Relson wrote:
> > ssh into box gives:
> >
> > PTY allocation request failed on channel 0
>
> Issue 'ls /dev/pt*' for me?
>
> > ### recently emerged packages ###
>
> How complete is this list? I assume you didn't reboot recently into a
> new kernel? Did you upgrade udev by any chance? The only other suspect
> that I see is util-linux, but you are on the stable version.
> >
> > app-crypt/gnupg-2.0.14
> > app-text/poppler-0.12.3-r3
> > dev-libs/libgcrypt-1.4.5
> > dev-util/global-5.7.7
> > media-libs/alsa-lib-1.0.21a
> > media-sound/alsa-headers-1.0.21
> > media-sound/alsa-utils-1.0.21-r1
> > sys-apps/util-linux-2.16.2
> > virtual/poppler-0.12.3-r1
> > virtual/poppler-glib-0.12.3-r2
> > virtual/poppler-utils-0.12.3-r1
>
> Cheers,
>
> W
>
> --
> Willie W. Wong
> wwong@math.princeton.edu Data aequatione quotcunque fluentes
> quantitae involvente fluxiones invenire et vice versa ~~~ I. Newton

On Sat, 6 Feb 2010 10:13:02 -0500
Willie Wong wrote:

> On Sat, Feb 06, 2010 at 10:00:33AM -0500, Willie Wong wrote:
> > How complete is this list? I assume you didn't reboot recently into
> > a new kernel?
>
> Also, if you did reboot recently (maybe into the same kernel), cat
> /etc/fstab for me?

It's been 3 weeks ...

FWIW, I've downgraded udev from 146-r1 to 141 (what was running 2
weeks ago) with no change in system behavior. Upgrading back to
146-r1 didn't fix or break anything additional.

On Sat, 6 Feb 2010 10:11:07 -0500
Willie Wong wrote:

> On Sat, Feb 06, 2010 at 08:33:44AM -0500, David Relson wrote:
> > This morning, all of the sudden, I'm encountering process creation
> > problems. The problems seem to affect only bash. There are no
> > problems starting X applications like firefox and open office.
>
> Also, can you log-in on a vc? If you are in X, hit ctrl-alt-f2 and try
> to log into the console?

Works fine ...

Looking at "ls -l /dev/vc*" I see timestamps of "2010-02-02 23:34". At
23:31 that day,

openrc was upgraded from 0.3.0-r1 to 0.6.0-r1.
sysvinit was upgraded from 2.86-r10 to 2.87-r

The openrc upgrade occured because I had noticed automounting of my
flash drives had stopped working. Attempts to restart udev had
failed because /etc/init.d/sysfs wasn't present and that generated a
baselayout related complaint (because I installed baselayout-2 months
ago). Aren't dependencies wonderful?

On Sat, Feb 06, 2010 at 04:08:58PM -0500, David Relson wrote:
> The output of "ls /dev/pt*" is suspiciously short:
>
> root@osage / # ls /dev/pts
> /dev/ptmx
>
> /dev/pts:

That's it? There's nothing under /dev/pts? And you have terminals
running in X?

> > On Sat, Feb 06, 2010 at 08:33:44AM -0500, David Relson wrote:
> > > This morning, all of the sudden, I'm encountering process creation
> > > problems. The problems seem to affect only bash. There are no
> > > problems starting X applications like firefox and open office.
> >
> > Also, can you log-in on a vc? If you are in X, hit ctrl-alt-f2 and try
> > to log into the console?
>
> Works fine ...
>
> Looking at "ls -l /dev/vc*" I see timestamps of "2010-02-02 23:34". At
> 23:31 that day,
>
> openrc was upgraded from 0.3.0-r1 to 0.6.0-r1.
> sysvinit was upgraded from 2.86-r10 to 2.87-r

This is possibly a problem. I am guessing that if you issue 'mount',
devpts is not mounted. The mounting of that pseudo filesystem is
relegated to /etc/init.d/devfs, which belongs to openrc.

What is the output of 'rc-status sysinit'?

W

--
Willie W. Wong wwong@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton

On Sat, 6 Feb 2010 17:27:14 -0500
Willie Wong wrote:

> On Sat, Feb 06, 2010 at 04:08:58PM -0500, David Relson wrote:
> > The output of "ls /dev/pt*" is suspiciously short:
> >
> > root@osage / # ls /dev/pts
> > /dev/ptmx
> >
> > /dev/pts:
>
> That's it? There's nothing under /dev/pts? And you have terminals
> running in X?
>
> > > On Sat, Feb 06, 2010 at 08:33:44AM -0500, David Relson wrote:
> > > > This morning, all of the sudden, I'm encountering process
> > > > creation problems. The problems seem to affect only bash.
> > > > There are no problems starting X applications like firefox and
> > > > open office.
> > >
> > > Also, can you log-in on a vc? If you are in X, hit ctrl-alt-f2
> > > and try to log into the console?
> >
> > Works fine ...
> >
> > Looking at "ls -l /dev/vc*" I see timestamps of "2010-02-02
> > 23:34". At 23:31 that day,
> >
> > openrc was upgraded from 0.3.0-r1 to 0.6.0-r1.
> > sysvinit was upgraded from 2.86-r10 to 2.87-r
>
> This is possibly a problem. I am guessing that if you issue 'mount',
> devpts is not mounted. The mounting of that pseudo filesystem is
> relegated to /etc/init.d/devfs, which belongs to openrc.
>
> What is the output of 'rc-status sysinit'?

Hi Willie,

Your replies are much appreciated as we're in an area of Linux about
which I'm poorly informed.

Output (below) of "rc-status sysinit" indicated devfs stopped, so I
started devfs (which didn't change /dev/pt*), then restarted udev
(which didn't affect /dev/pt*).

Regards,

David

### output follows ###


root@osage portage # rc-status sysinit
Runlevel: sysinit
dmesg [ stopped ]
udev [ started ]
devfs [ stopped ]

root@osage portage # service devfs status
* status: started

root@osage portage # rc-status sysinit
Runlevel: sysinit
dmesg [ stopped ]
udev [ started ]
devfs [ started ]

root@osage portage # ls /dev/pt*
/dev/ptmx

/dev/pts:

root@osage portage # service udev restart
* WARNING: you are stopping a sysinit service
* Stopping udevd ... [ ok ]
* Starting udevd ... [ ok ]
* Populating /dev with existing devices through uevents ... [ ok ]
* Waiting for uevents to be processed ... [ ok ]

root@osage portage # ls /dev/pt*
/dev/ptmx

/dev/pts:
root@osage portage #

On Sat, Feb 06, 2010 at 06:29:27PM -0500, David Relson wrote:
> Your replies are much appreciated as we're in an area of Linux about
> which I'm poorly informed.
>
> Output (below) of "rc-status sysinit" indicated devfs stopped, so I
> started devfs (which didn't change /dev/pt*), then restarted udev
> (which didn't affect /dev/pt*).

Right, but can you ssh in to the machine now (or open a terminal
emulator in X)?

/dev/pts is just the mount point for the devpts pseudo filesystem. In
modern versions of linux the pts devices are created on-the-fly when
requested (as opposed to other versions and some modern unixes where
there will be a fixed number of device nodes under /dev/pts or
equivalent). All that just goes to say that if /dev/pts is empty
right after you restart the devfs service, it is normal. A device file
should be created automatically now when userspace programs demand it.
(E.g. if you now ssh in, and if it succeeds, ls /dev/pts should show
one entry.)

Try it, let me know if the problem is still there.

Cheers,

W
--
Willie W. Wong wwong@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton