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

[Michael Mair-Keimberger]

On Fri, Mar 20, 2015 at 01:17:12PM -0400, Fernando Rodriguez wrote:
> 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.

Thanks for the link. I might have a look someday whats happening here as
i'm really curious and i really would like to build it over an chroot. I
already played around with stracing the "dead" pids but couldn't find any
useful information so far.
However after being tired of testing around i've decided to take the
easy way and compiled kdelibs on the raspberry pi directly. It took me
about 3 hours. Thats nothing compared for the hours playing around
already :) Interestingly i found that kdelibs isn't the only package
which hangs at some point.
I've installed kdelibs at my chroot as binary package and tried to
continue merging kdebase-meta. But after emerging about 20 other
packages, the compile stucked again. This time at kfind. I did the same
again (compile on rpi and installed it at my chroot as binary package)
and tried to continue again. Next package which stucked was kephal. At
this point i decided to merge the rest via the raspberry pi. 


>
> Have you tried a different qemu version?

Yep, tried following version:

app-emulation/qemu-2.1.2
app-emulation/qemu-2.2.0
app-emulation/qemu-2.2.1

No differences...
>
> --
> Fernando Rodriguez
>

-- 
greetings
Michael