[Pkg-xfce-devel] Bug#753168: xfce4-mailwatch-plugin: Please build against libgnutls28-dev

[Andreas Metzler]

On 2014-06-30 Yves-Alexis Perez <corsac at debian.org> wrote:
[...] 
> > Please build xfce4-mailwatch-plugin against libgnutls28-dev (and possibly
> > libgcrypt20-dev while you are at it) instead of libgnutls-dev, the
> > older GnuTLS version should not be part of jessie.

> Unfortunately, it seems that gnutls20 is not API compatible with
> gnutls11.

Hello,

It is mostly API compatible, in my tests xfce4-mailwatch-plugin
*built* successfuly against libgnutls28-dev (I had to manuall install
libgcrypt20-dev), no idea whether it works, though.

> For example, gcry_thread_cbs structure has changed (and is
> apparently obsolete, too). Is there some kind of porting guide?

I am not aware of a porting guide, no.

On my rebuilds I found two common issues:

* gnutls28 is not using gcrypt as crypto backend anymore, therefore
libgnutls28-dev does not automatically pull in gcrypt. Some programs
where using gcrypt directly for rather simple things because it was
pulled in anyway and now end up with an additional (build-)dependency.
Switching to GnuTLS crypto API avoids this ugliness.

* The gcry_thread_cbs thingy, which was was actually 
deprecated earlier in 2.12:
----------------------
** libgnutls: Added gnutls_global_set_mutex() to allow setting
alternative locking procedures. By default the system available
locking is used. In *NIX pthreads are used and in windows the
critical section API. This follows a different approach than the
previous versions that depended on libgcrypt initialization. The
locks are now set by default in systems that support it. Programs
that used gcry_control() to set thread locks should insert it into
a block of
#if GNUTLS_VERSION_NUMBER <= 0x020b00
        gcry_control(...)
#endif
----------------------
Most usages of this simply made sure the pthreads was used and can
basically be deleted/#ifdef. xfce4-mailwatch-plugin might be
different, needing to use gnutls_global_set_mutex(). See for an
example.

I am sorry I cannot be more helpful than that, the gnutls mailing
lists might offer more support.

cu Andreas
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