Bug#762959: ABI break: missing libclang.so.1

[Helmut Grohne]

Package: libclang1-3.5
Version: 1:3.5-2
Severity: serious
Control: affects -1 doxygen

Dear clang maintainers,

I noticed that installing doxygen in a fresh sid chroot results in an
unusable binary:

$ doxygen
doxygen: error while loading shared libraries: libclang.so.1: cannot open shared object file: No such file or directory
$

When installing doxygen with libclang1-3.5 version 1:3.5-1, this error
does not occur. When upgrading libclang1-3.5 from 1:3.5-1 to 1:3.5-2,
this error does not occur either. libclang.so.1 is only missing when
libclang1-3.5 was purged or never installed before installing 1:3.5-2.
Presumably something about the maintainer scripts changed.

Due to this bug in libclang1-3.5, currently 400+ reverse Build-Depends
of doxygen FTBFS (for example libpipeline). Please fix this quickly or
take care of the wave of bug reports that will soon arrive.

Helmut