From: Steve M. Robbins (steve_at_[hidden])
Date: 2008-05-01 12:27:13
On Thu, May 01, 2008 at 10:30:32AM -0400, David Abrahams wrote:
> on Thu Mar 13 2008, "Steve M. Robbins" <steve-AT-sumost.ca> wrote:
> > Actually, the only thing about Boost that causes grief to packagers is
> > that the toolset name (e.g. "gcc42") is embedded in the library
> > filename. I just wrote a response on Boost.Build outlining this in
> > some detail . Embedding the compiler version requires Debian to
> > rebuild all the boost packages each time a compiler change is made.
> > This is unnecessary when the compiler ABI is maintained (e.g 4.1 ->
> > 4.2) and also unnecessary when the ABI is broken, as Debian has
> > another mechanism to handle that. Note that rebuilding the boost
> > packages has a huge ripple effect, so it is more than simply
> > "unnecessary", it is a very large headache.
> I'm not sure that's the end of the story. One reason we embed the
> compiler name in the library name is that version-specific workarounds
> often show up in header files. The result is that when compiled against
> gcc-4.2, client code will effectively see different header contents than
> the precompiled boost library that was built with gcc-4.1 did.
Interesting. I didn't know that. Debian's "unstable" distribution
has been using the same compiled Boost libraries with a mix of GCC 4.1
and 4.2 since December. GCC 4.3 is being added to the mix, too.
I should grep the boost headers for BOOST_WORKAROUND to see what
differences might arise.
> I think we'd need to work out a discipline of avoiding
> BOOST_WORKAROUND code in headers that distinguishes compiler minor
> versions. I'm not very confident that I've thought that issue
> through completely... is it that simple?
If possible, that would be nice from a library distributor's
point of view.
> > The fact that Boost embeds the Boost version in the library name is
> > cause for grief to client software authors. But this is unavoidable
> > as long as Boost doesn't take care to maintain ABI across versions.
> > Fortunately, there is a simple solution to this, which I touch on in
> > my post .
> This is just a change to bjam? Have you gotten any traction with that
It turns out to be simpler than that. With a small tweak to boost's
Jamroot file, I'm now generating libraries without the toolset and
without the Boost version decorations. I will use this for the
upcoming Boost 1.35.0 Debian packages.
We had a long thread in Boost.Build about this idea . I'm not sure
I convinced anyone to my point of view. :-) We'll proceed with
Debian-specific changes for the short term and see how it goes.
 Thread starts at
The shortest statement of Debian's position is
(And please ignore http://lists.boost.org/boost-build/2008/04/18918.php
as I've changed my mind again)
Boost-Build list run by bdawes at acm.org, david.abrahams at rcn.com, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk