Re: gobject-introspection 1.86.0-1

On 17/03/2026 13:04, Takashi Yano via Cygwin wrote:
> Hi Jon,
> 
> Sorry for the late reply.

No problem! I understand that you have many other, more important 
demands on your time.

[...]
>> Hi Takashi,
>>
>> I just tripped over a small problem with gobject-introspection:
>>
>>> $ /usr/sbin/alternatives --set python3 /usr/bin/python3.12
>>>
>>> $ g-ir-scanner
>>> Traceback (most recent call last):
>>>    File "/usr/bin/g-ir-scanner", line 133, in <module>
>>>      from giscanner.scannermain import scanner_main
>>>    File "/usr/lib/gobject-introspection/giscanner/scannermain.py", line 35, in <module>
>>>      from giscanner.ast import Include, Namespace
>>>    File "/usr/lib/gobject-introspection/giscanner/ast.py", line 27, in <module>
>>>      from .sourcescanner import CTYPE_TYPEDEF, CSYMBOL_TYPE_TYPEDEF
>>>    File "/usr/lib/gobject-introspection/giscanner/sourcescanner.py", line 31, in <module>
>>>      from giscanner._giscanner import SourceScanner as CSourceScanner
>>> ModuleNotFoundError: No module named 'giscanner._giscanner'
>>
>> This fails because the _giscanner module is built for (and linked
>> against) python3.9.
> 
> Thanks for pointing this out.
> Currently, _giscanner is compiled as
> /usr/lib/gobject-introspection/giscanner/_giscanner.cpython-39-x86_64-cygwin.dll
> which perhaps requires libpython3.9.dll.
> 
>> I don't quite understand why this is happening since we configure with
>> "-Dpython=${PYTHON3}", so I'd expect end up with the full path to
>> specific python version in the shebang line in g-ir-scanner.
>>
>> (I think that's what was happening before upstream switched from
>> autotools to meson)
>>
>> In any case, this can be fixed in the cygport by using
>> python3_fix_shebang on this script.
> 
> Could you please let me know bit more detail how to use
> 'python3_fix_shebang'?

Sure.

In this case, I'd suggest adding a custom src_install which contains the 
default for the meson cygclass [1], then uses python3_fix_shebang[2].

> src_install() {
>  cd ${S}
>  meson_install
> 
>  python3_fix_shebang /usr/bin/g-ir-scanner
> }

The idea is that this adjusts the shebang line in the installed 
g-ir-scanner so it references python3.9, so that the import can be found 
(and thus it can be invoked successfully), irrespective of what version 
/usr/bin/python3 points to.

Unfortunately, when I actually try it, it seems that it can't handle 
'#!/usr/bin/env python3' and just rewrites the env part. How 
disappointing! That seems like a cygport bug :(

I guess you could just use something like this instead:

> sed -i -e "s#python3#${PYTHON3}#" ${D}/usr/bin/g-ir-scanner 

(But as I say, this all seems a bit like maybe an upstream bug that the 
python interpreter passed in via CYGMESON_ARGS doesn't end up there anyway?)


[1] 
https://cygwin.github.io/cygport/meson_cygclass.html#src_install%20(meson)
[2] 
https://cygwin.github.io/cygport/python3_cygclass.html#python3_fix_shebang


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