[Python] Cython fails builds on some machines with a CResult[shared_ptr[const Foo]]] declaration

[asfimport]

On the Conbench machines, the Cython code is failing to build:

Error compiling Cython file:
------------------------------------------------------------
...
        @staticmethod
        CStatus Open(const shared_ptr[CRandomAccessFile]& file,
                     CMemoryPool* pool,
                     unique_ptr[ORCFileReader]* reader)
 
        CResult[shared_ptr[const CKeyValueMetadata]] ReadMetadata()
                                ^
------------------------------------------------------------
 
pyarrow/_orc.pxd:42:33: Expected ']', found 'CKeyValueMetadata'

Cython appears not to like the CResult[shared_ptr[const CKeyValueMetadata]]], though this seems to only happen on some machines, even if using the same Cython version. Declaring a Status-returning variant seems to work around it.

Reporter: David Li / @lidavidm
Assignee: David Li / @lidavidm

PRs and other links:

• GitHub Pull Request #10417

_{Note: This issue was originally created as ARROW-12899. Please see the migration documentation for further details.}

[asfimport]

David Li / @lidavidm:
Upgrading Cython fixed it (it turns out 0.29.21 was being used, not 0.29.23)