Re: [OE-core] [PATCH] waf: explicitly run waf under Python 3

["Joshua Watt" <JPEWhacker@gmail.com>]

On 10/14/20 4:01 PM, Khem Raj wrote:
> On Wed, Oct 14, 2020 at 5:41 AM Joshua Watt <JPEWhacker@gmail.com> wrote:
>>
>>
>> On Wed, Oct 14, 2020, 6:26 AM Ross Burton <ross@burtonini.com> wrote:
>>> We don't assume Python 2 is on the host and don't expose an unversioned
>>> python in HOSTTOOLS, but waf uses the unversion python binary.
>>>
>>> Typically this is solved by patching waf (see the glmark2 recipe) but
>>> this can be solved centrally by invoking python3 directly.  All wscripts
>>> that needed Python 2 would have been fixed by now.
>>>
>>> Signed-off-by: Ross Burton <ross.burton@arm.com>
>>> ---
>>>   meta/classes/waf.bbclass | 8 ++++----
>>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/meta/classes/waf.bbclass b/meta/classes/waf.bbclass
>>> index 309f625a40..df6d4d53e8 100644
>>> --- a/meta/classes/waf.bbclass
>>> +++ b/meta/classes/waf.bbclass
>>> @@ -42,7 +42,7 @@ python waf_preconfigure() {
>>>       subsrcdir = d.getVar('S')
>>>       wafbin = os.path.join(subsrcdir, 'waf')
>>>       try:
>>> -        result = subprocess.check_output([wafbin, '--version'], cwd=subsrcdir, stderr=subprocess.STDOUT)
>>> +        result = subprocess.check_output(['python3', wafbin, '--version'], cwd=subsrcdir, stderr=subprocess.STDOUT)
>>
>> This will break our internal usage... We still use waf 1 which runs under python 2 only :(, although we are working on transitioning
> this is for master and we have already said goodbye to python2 in
> oe-core. perhaps reverse patching waf in your app might be an option ?

a.k.a. upgrading to waf 2 :)

Can we deal with it by importing either `pythonnative` or 
`python3native` in the recipes along with waf.bbclass, e.g.

     inherit waf pythonnative # waf 1

or

     inherit waf python3native # waf 2

Then you get the interpreter than matches the waf in your repo.

I do appreciate that oe-core has dumped python 2 support (and we should 
have *ages* ago also)... but I also don't really want a fire drill when 
most of our applications no longer build on 3.2, especially we can just 
inherit python3native as shown.

>
>>>           version = result.decode('utf-8').split()[1]
>>>           if StrictVersion(version) >= StrictVersion("1.8.7"):
>>>               d.setVar("WAF_EXTRA_CONF", "--bindir=${bindir} --libdir=${libdir}")
>>> @@ -55,16 +55,16 @@ python waf_preconfigure() {
>>>   do_configure[prefuncs] += "waf_preconfigure"
>>>
>>>   waf_do_configure() {
>>> -       (cd ${S} && ./waf configure -o ${B} --prefix=${prefix} ${WAF_EXTRA_CONF} ${EXTRA_OECONF})
>>> +       (cd ${S} && python3 ./waf configure -o ${B} --prefix=${prefix} ${WAF_EXTRA_CONF} ${EXTRA_OECONF})
>>>   }
>>>
>>>   do_compile[progress] = "outof:^\[\s*(\d+)/\s*(\d+)\]\s+"
>>>   waf_do_compile()  {
>>> -       (cd ${S} && ./waf build ${@oe.utils.parallel_make_argument(d, '-j%d', limit=64)} ${EXTRA_OEWAF_BUILD})
>>> +       (cd ${S} && python3 ./waf build ${@oe.utils.parallel_make_argument(d, '-j%d', limit=64)} ${EXTRA_OEWAF_BUILD})
>>>   }
>>>
>>>   waf_do_install() {
>>> -       (cd ${S} && ./waf install --destdir=${D} ${EXTRA_OEWAF_INSTALL})
>>> +       (cd ${S} && python3 ./waf install --destdir=${D} ${EXTRA_OEWAF_INSTALL})
>>>   }
>>>
>>>   EXPORT_FUNCTIONS do_configure do_compile do_install
>>> --
>>> 2.25.1
>>>
>>>
>>>
>>>
>> 
>>