How can I build a 32bit (i386) .deb on a 64bit box?

Question

I have applications which successfully compile with the -m32 switch (in DMD and/or GCC) to produce:

appname: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked
(uses shared libs), for GNU/Linux 2.6.15, not stripped

The source packages I have created work fine, on both 32 bit and 64 bit Ubuntu to build the appropriate binary .debs.

I would like to produce the i386 .deb on the same 64 bit machine i use to produce the 64 bit .deb.

Is this possible, and where should I look for instructions?

score 19 · Accepted Answer · answered Oct 31 '11 at 16:18

The answer depends on the complexity of your build. When the normal 64 bit userland tools suffice for a build, simply specify the architecture via -a

debuild -ai386

However, there are often cases where this doesn't work, and in these cases you'll need pbuilder. pbuilder builds a clean Debian/Ubuntu system in a chroot-ed environment. man pbuilder is a good introduction. To get started, you'll need:

sudo pbuilder --create --architecture i386
sudo pbuilder --build mypackage.dsc

To build a new package from scratch: `pdebuild --architecture i386` in the directory that contains debian/ directory. — Jahid, Aug 24 '15 at 15:25

score 3 · Answer 2 · edited Jul 31 '14 at 17:41

3

It starts with calling debuild with the -ai386 option, which will change the architecture that the package is built for.

Of course you have to ensure that the package contains the i386 build of the application.

edited Jul 31 '14 at 17:41

tshepang

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answered Oct 30 '11 at 12:37

James Westby

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he_the_great · Answer 3 · 2011-10-31T16:10:02.090

-2

You don't do anything thing different from building a 64bit .deb. Except that you include a 32bit build of your application.

The control file specifies the architecture, so be sure you select the correct one.

edited Oct 31 '11 at 16:10

answered Oct 29 '11 at 23:05

he_the_great

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Not true. Debian packages include the architecture of the package, which is explicitly specified. – Michael Mior Oct 29 '11 at 23:35
@Michael, so it is explicitly specified with the option that appears to have no documentation what-so-ever? – he_the_great Oct 30 '11 at 16:25
Actually, the structure of package control files is very well documented. Including the [Architecture](http://www.debian.org/doc/debian-policy/ch-controlfields.html#s-f-Architecture) option. – Michael Mior Oct 30 '11 at 21:38
@Michael, well yes, I was reading the other answer which mentions -ai386 and couldn't actually find it. Specifying the architecture is part of building a deb package, whether you are on amd64 or i386 the architecture selection is still part of the process. – he_the_great Oct 31 '11 at 03:46
Exactly. And it appears to be part of the process the OP has questions about. – Michael Mior Oct 31 '11 at 13:49

How can I build a 32bit (i386) .deb on a 64bit box?

3 Answers3