00check-network-cable fails with bad variable name

[Graeme Hewson]

Running ifup manually with my network configuration gives this error:

# ifup --verbose eth0
Configuring interface eth0=eth0 (inet6)
run-parts --exit-on-error --verbose /etc/network/if-pre-up.d
run-parts: executing /etc/network/if-pre-up.d/ethtool
run-parts: executing /etc/network/if-pre-up.d/wireless-tools
run-parts: executing /etc/network/if-pre-up.d/wpasupplicant
modprobe -q net-pf-10 > /dev/null 2>&1 || true # ignore failure.
sysctl -q -e -w net.ipv6.conf.eth0.use_tempaddr=2
sysctl -q -e -w net.ipv6.conf.eth0.accept_ra=2
sysctl -q -e -w net.ipv6.conf.eth0.autoconf=1
ip link set dev eth0 up
run-parts --exit-on-error --verbose /etc/network/if-up.d
run-parts: executing /etc/network/if-up.d/000resolvconf
run-parts: executing /etc/network/if-up.d/00check-network-cable
/etc/network/if-up.d/00check-network-cable: 72: local: detected:: bad variable name
run-parts: /etc/network/if-up.d/00check-network-cable exited with return code 2
Failed to bring up eth0

Running 00check-network-cable with dash -x shows what's happening:

# IFACE=eth0 dash -x 00check-network-cable
+ rc=/etc/default/network-test
+ [ ! -r /etc/default/network-test ]
[snip]
+ check_status_ethtool
+ local status=0
+ grep Link detected
+ /sbin/ethtool eth0
+ local LINK= Link detected: yes
00check-network-cable: 72: local: detected:: bad variable name

The code is saying to define a local variable called "detected:"; this
name comes from the output of the grep in line 72.

The solution is to declare LINK and assign to it in separate steps,
which I do in the attached patch.

I also remove the "true" (:) command from the original:

local LINK=$($ETHTOOL "$IFACE" 2>&1 | grep "Link detected" || :)

because it serves no purpose, as far as I can see.

(See also Debian bug 758798:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=758798 )

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "00check-network-cable.patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Javier Fernández-Sanguino (jfs)]

This bug was fixed in ifupdown-extra version 0.26 (uploaded to Debian in 2016):

Changes:
 ifupdown-extra (0.26) unstable; urgency=medium
 .
(...)
   * if-up-scripts/check-network-cable:
     - Fix the definition of LINK which fails due to variable name
     (Closes: #758798) (LP: 1397965)

[Javier Fernández-Sanguino (jfs)]

Fixed in version 0.26