Bug#729346: libidn: FTBFS if built twice in a row

[Wookey]

Package: libidn
Version: 1.28.1
Severity: normal

This package does not build if build twice in a row.

It appears to be bug #424522 returned from the dead.

It fails with:
dh_installdocs -A README NEWS TODO AUTHORS THANKS
        cp -a README debian/idn/usr/share/doc/idn
        cp -a NEWS debian/idn/usr/share/doc/idn
        cp -a TODO debian/idn/usr/share/doc/idn
        cp -a AUTHORS debian/idn/usr/share/doc/idn
        cp -a THANKS debian/idn/usr/share/doc/idn
        chown -R 0:0 debian/idn/usr/share/doc
        chmod -R go=rX debian/idn/usr/share/doc
        chmod -R u\+rw debian/idn/usr/share/doc
        install -g 0 -o 0 -m 644 -p debian/copyright 
debian/idn/usr/share/doc/idn/copyright
        cp -a doc/libidn.pdf debian/libidn11-dev/usr/share/doc/libidn11-dev
cp: cannot stat 'doc/libidn.pdf': No such file or directory
dh_installdocs: cp -a doc/libidn.pdf 
debian/libidn11-dev/usr/share/doc/libidn11-dev returned exit code 1

because libidn.pdf is delivered pre-built with the package but is removed by 
the clean target.
It should either be built, or not-cleaned.

(And if you try a 3rd time these files are changed too, which should be 
cleaned, but are not):
 libidn-1.28/doc/java/gjdoc.properties
 libidn-1.28/doc/java/gnu/inet/encoding/RangeSet.Builder.html
 libidn-1.28/doc/java/gnu/inet/encoding/RangeSet.Range.html
 libidn-1.28/doc/java/gnu/inet/encoding/RangeSet.html
 libidn-1.28/doc/java/resources/xhtml11-target10.dtd



-- System Information:
Debian Release: 7.2
  APT prefers stable
  APT policy: (990, 'stable')
Architecture: i386 (i686)

Kernel: Linux 3.2.0-kvm-i386-20110111 (SMP w/1 CPU core)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash