Automating architecture bootstrapping in Debian [LWN.net]

Automating architecture bootstrapping in Debian

Posted Sep 12, 2015 19:09 UTC (Sat) by giraffedata (guest, #1954)
Parent article: Automating architecture bootstrapping in Debian

If Build-Depends identifies things that have to be on the target system, what does Build-Depends mean in general, and why is the word "build" in it?

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Automating architecture bootstrapping in Debian

Posted Sep 13, 2015 19:47 UTC (Sun) by guillemj (subscriber, #49706) [Link] (4 responses)

No, «Build-Depends» specifies what needs to be installed on the build system (in contrast to the host or target systems, as Debian uses the GNU nomenclature) when building the package. In this case the “Build” refers to the act of building, not the system. «Depends» OTOH specifies what needs to be installed on the host system, when installing the built package.

Automating architecture bootstrapping in Debian

Posted Sep 13, 2015 19:53 UTC (Sun) by giraffedata (guest, #1954) [Link] (3 responses)

How do you reconcile that with (from the article):

Build-Depends: g++ (>= 4:5) is probably meant to specify that the package should be built with a recent version of G++, but the rule is interpreted as a package that needs to be present on the target system.

"probably meant ..." sounds to me like what you say, whereas "is interpreted as ..." does not.

Automating architecture bootstrapping in Debian

Posted Sep 14, 2015 7:14 UTC (Mon) by helmut (guest, #104440) [Link] (1 responses)

Maybe the "on the target system" part is misleading and it should say "for the target system" instead? Build-Depends really describe what is to be installed on the build system, but in a cross build setting those packages can be instances for multiple architectures, namely the system you are building on and the system you are building for. So this particular dependency ends up requesting a compiler that cannot be run on the build system.

Automating architecture bootstrapping in Debian

Posted Sep 18, 2015 11:17 UTC (Fri) by pboddie (guest, #50784) [Link]

I think that there might be two factors under consideration:

A package needs to build host executables during the build process that then process files for eventual installation.
A package needs to build target executables.

So, the Build-Depends might be asking for a compiler that can fulfil purpose (1) or (2) or even both.

Automating architecture bootstrapping in Debian

Posted Oct 10, 2015 7:02 UTC (Sat) by mcortese (guest, #52099) [Link]

I had the same problem reading that paragraph, and I still don't fully understand it even after the explanations given in the comments. This may be the symptom that there's indeed something to change in that area!