Re: [PATCH 4/4] scripts/qmp: Fix QEMU Python scripts path

[Markus Armbruster <armbru@redhat.com>]

John Snow <jsnow@redhat.com> writes:

> On 4/21/20 5:42 AM, Philippe Mathieu-Daudé wrote:
>> QEMU Python scripts have been moved in commit 8f8fd9edba4 ("Introduce
>> Python module structure"). Use the same sys.path modification used
>> in the referenced commit to be able to use these scripts again.
>> 
>> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
>> ---
>>  scripts/qmp/qmp      | 4 +++-
>>  scripts/qmp/qom-fuse | 4 +++-
>>  scripts/qmp/qom-get  | 4 +++-
>>  scripts/qmp/qom-list | 4 +++-
>>  scripts/qmp/qom-set  | 4 +++-
>>  scripts/qmp/qom-tree | 4 +++-
>>  6 files changed, 18 insertions(+), 6 deletions(-)
>> 
>> diff --git a/scripts/qmp/qmp b/scripts/qmp/qmp
>> index 0625fc2aba..8e52e4a54d 100755
>> --- a/scripts/qmp/qmp
>> +++ b/scripts/qmp/qmp
>> @@ -11,7 +11,9 @@
>>  # See the COPYING file in the top-level directory.
>>  
>>  import sys, os
>> -from qmp import QEMUMonitorProtocol
>> +
>> +sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
>> +from qemu.qmp import QEMUMonitorProtocol
>>  
>
> Try to avoid using sys.path hacks; they don't work in pylint or mypy and
> it provides an active barrier to CQA work here.
> (They also tend to be quite fragile.)
>
> We can discuss the right way to do this; one of those ways is to create
> an installable package that we can install locally in a virtual environment.
>
> Another way is perhaps to set PYTHONPATH in the calling environment so
> that standard "import" directives will work.
>
> Both ultimately involve changing the environment of the user to
> accommodate the script.

For what it's worth, tests/Makefile.involve does the latter for
tests/qapi-schema/test-qapi.py.  Simple enough, but makes manual
invocation inconvenient.

Not necessary for scripts/qapi-gen.py, because its "import qmp.FOO"
finds qmp right in scripts/qmp/.