Re: [gentoo-user] unable to compile kdelibs in arm chroot

[Fernando Rodriguez]

On Friday, March 20, 2015 10:15:03 AM Michael Mair-Keimberger wrote:
> On Thu, Mar 19, 2015 at 04:44:55PM -0400, Fernando Rodriguez wrote:
> > On Thursday, March 19, 2015 9:11:02 PM Michael Mair-Keimberger wrote:
> > > Hi List,
> > >
> > > For the last few weeks i was playing around with my newly acquired
> > > raspberry pi 2. While it was pretty easy to setup a working gentoo
> > > stage3 system i failed installing anything below the basic packages.
> > > Generally my idea was building the arm packages on any system and
> > > provide them as binary packages for other raspberry pi's (yeah, i
> > > already bought my second rpi :D)
> > >
> > > At first, my idea was to build all the packages directly on the rpi.
(with
> > > /var/tmp & /usr/portage on a external harddisk). However, the compile
> > > times are worse than i expected so i abandoned the idea.
> > >
> > > Next i've played around with crossdev. It sort of worked, but i never
> > > could finish compiling xorg-server. (or basic system packages) Even
> > > though i've started over and over with different settings, there were
> > > always packages which failed to compile thus doesn't let me finish
> > > xorg-server. I might look into it some other day but now i just wanted
> > > something working.
> > >
> > > Now i'm playing with using qemu-arm [1][2] in order to compile the
> > > packages inside a chroot. This is - so far - the most promising method
> > > building packages, even though the compile times are worse than with
> > > crossdev, but still better than directly on the rpi.
> > >
> > > So far i finally could compile xorg-server and also updated the whole
> > > system, which, at this point, wasn't much anyway. My next goal was kde.
> > > I've compiled about half of all packages which are required for
> > > kdebase-meta, but now i'm stuck at kdelibs and i have no idea what's
> > > wrong.
> > >
> > > The problem:
> > >
> > > The problem is, the compile doesn't fail - it just hangs/stops. At some
> > > point (which seems to be random - it can stop anywhere between 1% and
> > > 100% of the compile) the compile stops and does nothing. I've waited
> > > hours, but nothing happened.
> > > So far i tried lots of things, for example:
> > > * MAKEOPTS="-j1" and/or FEATURES="-sandbox"
> > > * also tried without building binary packages (-buildpkg)
> > > * /var/tmp on tmpfs
> > > * using: ebuild /usr/portage/kde-base/..../kdelibs....ebuild compile
> > > * using python3.3 instead of default 2.7
> > > * moved it on a different system and tried building it there (again with
> > > many different settings)
> > >
> > > Nothing worked, even though the build moved until 100% two times (-_-)
> > >
> > > I have no idea what the problem is. Even qtwebkit, which took way longer
> > > to compile (about 3 hours) compiled on the first try. (which should
> > > exclude temperate and/or resource problems)
> > > I also don't think it's a problem with a use flag as the build stops
> > > anywhere - i couldn't find a pattern. It seems to be completely random.
> > >
> > > Any ideas whats wrong or how to fix this? Any help would be much
> > > appreciated as i'm out of ideas :(
> > >
> > > Thx
> > >
> > > [1] https://www.gentoo.org/proj/en/base/embedded/handbook/?part=1&chap=5
> > > [2] http://wiki.gentoo.org/wiki/Crossdev_qemu-static-user-chroot
> >
> > One possibility is swap trashing (running so low in RAM that every
instruction 
> > takes several swaps to execute), especially with /var/tmp on tmpfs! This
can 
> > happen even if you don't have a swap partition. Try with either more RAM
or 
> > /var/tmp on a physical filesystem.
> >
> Usually /var/tmp is on the physical filesystem anyway. I've tried it
> just once or twice because i though about a performance problem. RAM
> shouldn't be a problem too as i'm having 16GB of RAM available.
> >

I would tell you to attach a debugger and see if you can tell why it's hanging 
but that may not be worth the trouble (since it'll be a child process that's 
hanging it'll be tricky to start qemu with the gdb stub just for that 
process). If you want to try it see: http://tinkering-is-fun.blogspot.com/2009/12/debugging-non-native-programs-with-qemu.html and 
search QEMU_GDB for the tricky part.

Have you tried a different qemu version?

-- 
Fernando Rodriguez