Bug#788580: pbuilder: No more mounts /dev/pts inside the chroot if host is running systemd 220, causing packages to FTBFS

[Axel Beckert]

Package: pbuilder
Version: 0.215+nmu3
Severity: important
Tags: sid stretch
Control: affects -1 src:zsh

Dear Maintainer,

if pbuilder is running on a host which uses systemd >= 220 as init
system (i.e. on Sid with systemd), it no more mounts /dev/pts inside the
chroot which makes some packages (e.g. zsh) FTBFS.

Even explicitly setting USEDEVPTS=yes in /etc/pbuilderrc does _not_
help and /dev/pts is not mounted in the chroot.

Interestingly it still tries to unmount /dev/pts inside the chroot after
the failed build:

dpkg-buildpackage: error: debian/rules build gave error exit status 2
E: Failed autobuilding of package
W: no hooks of type C found -- ignoring
I: unmounting dev/pts filesystem
W: Could not unmount dev/pts: umount: /var/cache/pbuilder/build//28745/dev/pts: not mounted
W: Ignored error in unmount
I: unmounting run/shm filesystem
I: unmounting proc filesystem
I: cleaning the build env

The issue can be workarounded by any of the following actions:

* booting the host system with sysvinit instead of systemd
* downgrading systemd on the host system to 215-18 as currently in
  testing.
* Using pbuilder login and calling "mount -t devpts none /dev/pts".

I've stumbled upon this when packaging a new zsh upstream which builds
fine if

* built outside the chroot,
* built with the very same pbuilder version but on Jessie (systemd 215),
* built with the very same pbuilder version on Sid but running sysvinit,

but FTBFS due to pty related test suite failures if built with pbuilder
on Sid with systemd (220). Example failing test (there are several tests
failing):

../../Test/V08zpty.ztst: starting.
Running test: zpty with a process that does not set up the terminal: internal write
Test ../../Test/V08zpty.ztst failed: bad status 1, expected 0 from:
  zpty cat cat
  zpty -w cat a line of text
  var=
  zpty -r cat var && print -r -- ${var%%$'\r\n'}
  zpty -d cat
Error output:
(zpty):zpty:1: can't open pseudo terminal: no such file or directory
(eval):zpty:2: no such pty command: cat
(eval):zpty:4: no such pty command: cat
(eval):zpty:5: no such pty command: cat
Was testing: zpty with a process that does not set up the terminal: internal write
../../Test/V08zpty.ztst: test failed.

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (600, 'testing'), (111, 'buildd-unstable'), (111, 'buildd-experimental'), (110, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.0.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages pbuilder depends on:
ii  coreutils              8.23-4
ii  debconf [debconf-2.0]  1.5.56
ii  debianutils            4.5.1
ii  debootstrap            1.0.70
ii  dpkg-dev               1.18.1
ii  wget                   1.16.3-2+b2

Versions of packages pbuilder recommends:
ii  devscripts  2.15.5
ii  fakeroot    1.20.2-1
ii  iproute2    3.16.0-2
ii  net-tools   1.60-26+b1
ii  sudo        1.8.12-1

Versions of packages pbuilder suggests:
ii  cowdancer     0.73
ii  gdebi-core    0.9.5.5+nmu1
pn  pbuilder-uml  <none>

-- debconf information:
  pbuilder/mirrorsite: http://ftp.ch.debian.org/debian/
  pbuilder/rewrite: false
  pbuilder/nomirror: