Installing default-jdk, uninstalling it, doing apt-get autoremove, and reinstalling it leaves you without /usr/bin/javac ?

[Dan Kegel]

To reproduce:

$ sudo lxc-create -t ubuntu -n testbot01-ubu1004-test -- -r lucid
$ sudo lxc-start -n testbot01-ubu1004-test
(log in)
$ sudo apt-get install default-jdk
$ which javac
/usr/bin/javac
$ sudo apt-get remove default-jdk
$ which javac
/usr/bin/javac
$ sudo apt-get autoremove -y
$ which javac
$ sudo apt-get install default-jdk
$ which javac
$ update-java-alternatives -l
java-1.6.0-openjdk 1061 /usr/lib/jvm/java-1.6.0-openjdk
$ sudo update-java-alternatives -a
update-alternatives: error: no alternatives for appletviewer.
update-alternatives: error: no alternatives for extcheck.
...
$ apt-cache policy default-jdk
default-jdk:
  Installed: 1.6-34
  Candidate: 1.6-34
  Version table:
 *** 1.6-34 0
        500 http://archive.ubuntu.com/ubuntu/ lucid/main Packages
        100 /var/lib/dpkg/status

If you save a log on the two 'apt-get install default-jdk' lines, diffing the two shows:

 Setting up openjdk-6-jre-headless (6b27-1.12.6-1ubuntu0.10.04.4) ...
-update-alternatives: using /usr/lib/jvm/java-6-openjdk/jre/bin/java to provide /usr/bin/java (java) in auto mode.
...
 Setting up openjdk-6-jdk (6b27-1.12.6-1ubuntu0.10.04.4) ...
-update-alternatives: using /usr/lib/jvm/java-6-openjdk/bin/appletviewer to provide /usr/bin/appletviewer (appletviewer) in auto mode.

So evidently there's some sort of postinst / postrm problem that only shows up on the second install?

[Dan Kegel (dank)]

Oh, and the host OS was Ubuntu 12.04.4 LTS, if that matters.

[Dan Kegel (dank)]

The postinst script for openjdk-6-jdk_6b27-1.12.6-1ubuntu0.10.04.4_amd64.deb says:

case "$1" in
configure)
    # obsolete tool
    if update-alternatives --list apt 2>/dev/null; then
        update-alternatives --remove-all apt || true
    fi

    if [ -z "$2" ]; then
        update_alternatives=y
    fi

...

https://www.debian.org/doc/debian-policy/ch-maintainerscripts.html says $2 is " most-recently-configured-version".

Thus it looks like a thinko ... the author of the postinst script thought $2 meant something else, or forgot that the postrm script removed the alternatives?

The same test appears to be present in ubuntu 12.04's openjdk-7-jdk_7u51-2.4.4-0ubuntu0.12.04.2_amd64.deb,
but I haven't verified yet whether the problem occurs there as well.

[Dan Kegel (dank)]

Running 'apt-get purge openjdk-6-jdk' instead of (or after) removing openjdk-6-jdk appears to work around
the problem; the next install does put /usr/bin/javac in place.

[Dan Kegel (dank)]

Correction: apt-get purge openjdk-6-jdk *after* uninstalling it does not work around it (it refuses to purge
because the package isn't installed).
The correct workaround if you know the package is uninstalled is sudo dpkg --purge openjdk-6-jdk.

The problem is present if the package is not installed but is configured, e.g. if you see:

$ dpkg-query -l openjdk-6-jdk
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Description
+++-=========================-=========================-==================================================================
rc openjdk-6-jdk 6b27-1.12.6-1ubuntu0.10.0 OpenJDK Development Kit (JDK)

instead of

$ dpkg-query -l openjdk-6-jdk
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Description
+++-=========================-=========================-==================================================================
un openjdk-6-jdk <none> (no description available)