On Monday, 26 בMarch 2012 11:32:10 Richard W.M. Jones wrote:

> On Mon, Mar 26, 2012 at 12:57:44AM +0200, Oron Peled wrote:

> > - This means that a Debian/Ubuntu workstation can build both .deb

> > and RPM packages, and we cannot use Fedora for a similar role.

>

> Is this really true? What happens if, say, your program depends on

> PCRE, which has different sonames on Debian/Ubuntu and Fedora (for

> essentially the same library):

You are correct that packaging tools by themselves do not solve *all*

portability problems (e.g: Suse/Mandriva/Feodra use RPM, but nobody

sane would try to install cross-distro -- even with same package format)

However, there are many important working use-cases.

Examples:

* If the programs or libraries you compile yourselve, use just glibc,

you are normally good to go (due to the very strict ABI provided

by glibc):

oron@squeeze1:~$ objdump --all /lib/libc-2.11.3.so | grep SONAME

SONAME libc.so.6

[oron@localhost ~]$ rpm -q fedora-release

fedora-release-15-3.noarch

[oron@localhost ~]$ objdump --all /lib/libc-2.14.1.so | grep SONAME

SONAME libc.so.6

* Noarch packages (perl/python/ruby/you-name-it)

* Packaging cross-compiler toolchain/libraries (which is really

a special case of the two previous items)

* Manipulating packages:

- createrepo

- downloading/extracting source packages

> I don't understand how a binary built on one platform could be copied

> across to the other and work.

Moreover, if we have pbuilder on Fedora (which is one of the packages

I listed), we are done, as it build in a chroot environment (similar

to Fedora's mock).

Actually, even when building on a Debian host I always use either

pbuilder(1) for unattended builds, or build in an schroot(1) for

interactive builds. This enables me to build the same source tree

(maybe with pending commits) for different OS releases.

[Note: schroot(1) is already packaged in Fedora -- anybody who didn't

try it is missing a crown jewl]

--

Oron Peled Voice: +972-4-8228492

oron@actcom.co.il http://users.actcom.co.il/~oron

"The future is here, it's just not evenly distributed yet."

- William Gibson