Re: python3 script header and rhel8

[Daniel P . Berrangé]

On Tue, Jan 28, 2020 at 03:44:04PM +0000, Vladimir Sementsov-Ogievskiy wrote:
> Hi all!
> 
> Hmm Qemu dropped support for python2, and anyway python2 is not supported now 
> at all.
> 
> Still, we have a lot of "#!/usr/bin/env python" headings in our scripts, 
> which is
> unsupported by rhel8 by default. So, for example, because of such line in
> tests/qemu-iotests/nbd-fault-injector.py, iotest 277 fails.
> 
> Of course, it's simple to set python in rhel8 to be python3... But should we 
> fix
> all the headings to be "#!/usr/bin/env python3"? Or what is the correct 
> heading
> for scripts in a new python3 world?

Using "#!/usr/bin/env python3" is probably our best choice, as it
makes it absolutely clear we're not happy with a python2 impl.

> # git grep -l '^#!/usr/bin/env python$'
> scripts/analyse-9p-simpletrace.py
> scripts/analyse-locks-simpletrace.py
> scripts/decodetree.py
> scripts/device-crash-test
> scripts/kvm/kvm_flightrecorder
> scripts/qapi-gen.py
> scripts/render_block_graph.py
> scripts/replay-dump.py
> scripts/simpletrace.py
> scripts/tracetool.py
> scripts/tracetool/__init__.py
> scripts/tracetool/backend/__init__.py
> scripts/tracetool/backend/dtrace.py
> scripts/tracetool/backend/ftrace.py
> scripts/tracetool/backend/log.py
> scripts/tracetool/backend/simple.py
> scripts/tracetool/backend/syslog.py
> scripts/tracetool/backend/ust.py
> scripts/tracetool/format/__init__.py
> scripts/tracetool/format/c.py
> scripts/tracetool/format/d.py
> scripts/tracetool/format/h.py
> scripts/tracetool/format/log_stap.py
> scripts/tracetool/format/simpletrace_stap.py
> scripts/tracetool/format/stap.py
> scripts/tracetool/format/tcg_h.py
> scripts/tracetool/format/tcg_helper_c.py
> scripts/tracetool/format/tcg_helper_h.py
> scripts/tracetool/format/tcg_helper_wrapper_h.py
> scripts/tracetool/format/ust_events_c.py
> scripts/tracetool/format/ust_events_h.py
> scripts/tracetool/transform.py
> scripts/tracetool/vcpu.py

IMHO the '#!/usr/bin/env' header should only be added to files
which are executable scripts - ie a main() method. IOW, it
ought to be removed from all these tracetool modules.

> tests/acceptance/virtio_seg_max_adjust.py
> tests/acceptance/x86_cpu_model_versions.py
> tests/docker/travis.py
> tests/qapi-schema/test-qapi.py
> tests/qemu-iotests/030
> tests/qemu-iotests/040
> tests/qemu-iotests/041
> tests/qemu-iotests/044
> tests/qemu-iotests/045
> tests/qemu-iotests/055
> tests/qemu-iotests/056
> tests/qemu-iotests/057
> tests/qemu-iotests/065
> tests/qemu-iotests/093
> tests/qemu-iotests/096
> tests/qemu-iotests/118
> tests/qemu-iotests/124
> tests/qemu-iotests/129
> tests/qemu-iotests/132
> tests/qemu-iotests/136
> tests/qemu-iotests/139
> tests/qemu-iotests/147
> tests/qemu-iotests/148
> tests/qemu-iotests/149
> tests/qemu-iotests/151
> tests/qemu-iotests/152
> tests/qemu-iotests/155
> tests/qemu-iotests/163
> tests/qemu-iotests/165
> tests/qemu-iotests/169
> tests/qemu-iotests/194
> tests/qemu-iotests/196
> tests/qemu-iotests/199
> tests/qemu-iotests/202
> tests/qemu-iotests/203
> tests/qemu-iotests/205
> tests/qemu-iotests/206
> tests/qemu-iotests/207
> tests/qemu-iotests/208
> tests/qemu-iotests/209
> tests/qemu-iotests/210
> tests/qemu-iotests/211
> tests/qemu-iotests/212
> tests/qemu-iotests/213
> tests/qemu-iotests/216
> tests/qemu-iotests/218
> tests/qemu-iotests/219
> tests/qemu-iotests/222
> tests/qemu-iotests/224
> tests/qemu-iotests/228
> tests/qemu-iotests/234
> tests/qemu-iotests/235
> tests/qemu-iotests/236
> tests/qemu-iotests/237
> tests/qemu-iotests/238
> tests/qemu-iotests/242
> tests/qemu-iotests/245
> tests/qemu-iotests/246
> tests/qemu-iotests/248
> tests/qemu-iotests/254
> tests/qemu-iotests/255
> tests/qemu-iotests/256
> tests/qemu-iotests/257
> tests/qemu-iotests/258
> tests/qemu-iotests/260
> tests/qemu-iotests/262
> tests/qemu-iotests/264
> tests/qemu-iotests/266
> tests/qemu-iotests/277
> tests/qemu-iotests/280
> tests/qemu-iotests/nbd-fault-injector.py
> tests/qemu-iotests/qcow2.py
> tests/qemu-iotests/qed.py
> tests/vm/basevm.py
> tests/vm/centos
> tests/vm/fedora
> tests/vm/freebsd
> tests/vm/netbsd
> tests/vm/openbsd
> tests/vm/ubuntu.i386

Regards,
Daniel
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