Re: [Xen-devel] Hypervisor build can't work without `python` (Was: Re: Xen commit 9b0bc91b3 possibly removed too much info from README)

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Wed, Apr 17, 2019 at 12:15:04PM +0100, Andrew Cooper wrote:
> On 17/04/2019 12:03, Wei Liu wrote:
> > On Wed, Apr 17, 2019 at 11:58:49AM +0100, Andrew Cooper wrote:
> >> On 17/04/2019 11:57, Wei Liu wrote:
> >>> On Wed, Apr 17, 2019 at 11:44:36AM +0100, Andrew Cooper wrote:
> >>>> On 17/04/2019 11:41, Wei Liu wrote:
> >>>>> On Wed, Apr 17, 2019 at 10:56:57AM +0100, Wei Liu wrote:
> >>>>>>> Here's what i did having pulled the master at commit cb70a26
> >>>>>>>
> >>>>>>> tar xf /path/to/xen-cb70a26.tar.gz
> >>>>>>>
> >>>>>>> cd xen-master/
> >>>>>>>
> >>>>>>> PYTHON=/usr/bin/python3 ./configure --prefix=/usr   \
> >>>>>>>    --disable-seabios   \
> >>>>>>>    --disable-qemu-traditional  \
> >>>>>>>    --disable-rombios     \
> >>>>>>>    --disable-stubdom 2>&1 | tee ../config.log
> >>>>>>>
> >>>>>>> make EFI_DIR=/usr/lib/efi world 2>&1 | tee ../make_world_3.out
> >>>>>>>
> >>>>>>>
> >>>>>>> ...
> >>>>>>> gcc -Wp,-MD,tools/kconfig/.zconf.tab.o.d    -D_GNU_SOURCE
> >>>>>>> -D_DEFAULT_SOURCE -DCURSES_LOC="<ncurses.h>" -DNCURSES_WIDECHAR=1
> >>>>>>> -DLOCALE  -Itools/kconfig -c -o tools/kconfig/zconf.tab.o
> >>>>>>> tools/kconfig/zconf.tab.c
> >>>>>>> gcc  -o tools/kconfig/conf tools/kconfig/conf.o 
> >>>>>>> tools/kconfig/zconf.tab.o
> >>>>>>> tools/kconfig/conf -s --silentoldconfig Kconfig
> >>>>>>> make[3]: Leaving directory '/usr/src/xen/xen-master/xen'
> >>>>>>> make -f Rules.mk _install
> >>>>>>> make[3]: Entering directory '/usr/src/xen/xen-master/xen'
> >>>>>>> make -C tools
> >>>>>>> make[4]: Entering directory '/usr/src/xen/xen-master/xen/tools'
> >>>>>>> make symbols
> >>>>>>> make[5]: Entering directory '/usr/src/xen/xen-master/xen/tools'
> >>>>>>> gcc -Wall -Werror -Wstrict-prototypes -O2 -fomit-frame-pointer
> >>>>>>> -fno-strict-aliasing -Wdeclaration-after-statement -o symbols
> >>>>>>> symbols.c
> >>>>>>> make[5]: Leaving directory '/usr/src/xen/xen-master/xen/tools'
> >>>>>>> make[4]: Leaving directory '/usr/src/xen/xen-master/xen/tools'
> >>>>>>> make -f /usr/src/xen/xen-master/xen/Rules.mk include/xen/compile.h
> >>>>>>> make[4]: Entering directory '/usr/src/xen/xen-master/xen'
> >>>>>>>  Xen 4.13-unstable
> >>>>>>> /bin/sh: python: command not found
> >>>>>>> make[4]: *** [Makefile:169: include/xen/compile.h] Error 127
> >>>>>> Here. The PYTHON invocation is from the hypervisor build, not the tools
> >>>>>> build.
> >>>>>>
> >>>>>> Thanks for the log.  I will have a closer look.
> >>>>>>
> >>>>>>> make[4]: Leaving directory '/usr/src/xen/xen-master/xen'
> >>>>>>> make[3]: *** [Makefile:137: /usr/src/xen/xen-master/xen/xen] Error 2
> >>>>>>> make[3]: Leaving directory '/usr/src/xen/xen-master/xen'
> >>>>>>> make[2]: *** [Makefile:45: install] Error 2
> >>>>>>> make[2]: Leaving directory '/usr/src/xen/xen-master/xen'
> >>>>>>> make[1]: *** [Makefile:123: install-xen] Error 2
> >>>>>>> make[1]: Leaving directory '/usr/src/xen/xen-master'
> >>>>>>> make: *** [Makefile:165: world] Error 2
> >>>>>>>
> >>>>>>>
> >>>>>>> Note the
> >>>>>>>
> >>>>>>> /bin/sh: python: command not found
> >>>>>>>
> >>>>> The issue here is on LFS there is no /usr/bin/python. So the hypervisor
> >>>>> build is broken because xen/include/compile.h invokes
> >>>>>
> >>>>>  @$(PYTHON) tools/fig-to-oct.py < .banner >> $@.new
> >>>>>
> >>>>> There are other appearances of PYTHON in hypervisor build, which are
> >>>>> equally broken.
> >>>>>
> >>>>> We had / have a policy to avoid making hypervisor build dependent on
> >>>>> configure. I have CC'ed more people on their opinions.
> >>>> Where has $(PYTHON) got lost?  It was specified correctly to begin with.
> >>> Where is it specified?
> >> Oh - I see now.
> >>
> >> It is specified for ./configure, but not for make.
> > Right.
> >
> > It works for tools because tools build includes config/Tools.mk which
> > contains the correct python path. Tools.mk is generated by configure.
> >  
> > Obviously hypervisor build shouldn't include Tools.mk. Furthermore, the
> > policy of "hv shouldn't depend on configure" makes this route a no-go.
> >
> > Either we change the policy, or we document the deficiency, or we come
> > up with some clever trick to probe.
> 
> Given the shebang in all of our scripts, would `env python` be
> sufficiently clever trickery, or is that a can of worms we'd prefer not
> to open?

I already tried env python -- it didn't work. I think it searches PATHS
just like a shell would.

Wei.

> 
> ~Andrew

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel