Re: [Bug 1883560] [NEW] mips linux-user builds occasionly crash randomly only to be fixed by a full clean re-build

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 18 Jun 2020 19:00:34 +0200
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> wrote:

> четвртак, 18. јун 2020., Cornelia Huck <cohuck@redhat.com> је написао/ла:
> 
> > On Mon, 15 Jun 2020 15:18:48 -0000
> > Alex Bennée <1883560@bugs.launchpad.net> wrote:
> >  
> > > Public bug reported:
> > >  
> > > >From time to time I find check-tcg crashes with a one of the MIPS  
> > > binaries. The last time it crashed was running the test:
> > >
> > >   ./mips64el-linux-user/qemu-mips64el ./tests/tcg/mips64el-linux-
> > > user/threadcount
> > >
> > > Inevitably after some time noodling around wondering what could be
> > > causing this weird behaviour I wonder if it is a build issue. I wipe all
> > > the mips* build directories, re-run configure and re-build and voila
> > > problem goes away.
> > >
> > > It seems there must be some sort of build artefact which isn't being
> > > properly re-generated on a build update which causes weird problems.
> > > Additional data point if I:
> > >
> > >   rm -rf mips64el-linux-user
> > >   ../../configure
> > >   make
> > >
> > > then I see failures in mip32 builds - eg:
> > >
> > >     GEN     mipsn32el-linux-user/config-target.h
> > >   In file included from /home/alex/lsrc/qemu.git/  
> > linux-user/syscall_defs.h:10,  
> > >                    from /home/alex/lsrc/qemu.git/linux-user/qemu.h:16,
> > >                    from /home/alex/lsrc/qemu.git/  
> > linux-user/linuxload.c:5:  
> > >   /home/alex/lsrc/qemu.git/linux-user/mips64/syscall_nr.h:1: error:  
> > unterminated #ifndef  
> > >    #ifndef LINUX_USER_MIPS64_SYSCALL_NR_H
> > >
> > >   make[1]: *** [/home/alex/lsrc/qemu.git/rules.mak:69:  
> > linux-user/linuxload.o] Error 1  
> > >   make[1]: *** Waiting for unfinished jobs....
> > >
> > > which implies there is a cross dependency between different targets
> > > somewhere. If I executed:
> > >
> > >   rm -rf mips*
> > >
> > > before re-configuring and re-building then everything works again.
> > >
> > > ** Affects: qemu
> > >      Importance: Undecided
> > >          Status: New
> > >
> > >
> > > ** Tags: build linux-user mips
> > >  
> >
> > FWIW, this does not seem to be a mips-only issue: I'm seeing the
> > threadcount test fail with s390x-linux-user as well, and it also goes
> > away (only) if I purge the build directory, re-configure, and re-build.
> >
> >
> >  
> Alex, Cornelia,
> 
> Do you perhaps recall how did you obtain the original binaries (those with
> the problem)? What would be your typical workflow? Perhaps "git-pull +
> make" on existing, but not latest source tree?

Just a bog-standard "pull some stuff, do make, create a branch and put
some patches on it, do make, switch to another branch, do make, etc". No
advanced fiddling with git history, doing make on a subtree, etc.