Re: python3.13 fails to build on macOS 26

[Adam <adam%netbsd.org@localhost>]

>> and then expat_config.h is not in bl3 and the build doesn't find it.
> 
> This is because python wants newfangled expat_config.h, missing in macOS
> system expat (and NetBSD system expat until well after 11).  I have
> extended the "prefer pkgsrc" conditional and not yet committed it.
> 
> The next  problem is
> 
>  [ERROR] _elementtree failed to import: pyexpat version is incompatible
>  Following modules built successfully but were removed because they could not be imported:
>  _elementtree
> 
> and I continue to wonder if anyone has built python313 on macOS 26,
> using default bootstrap settings.

I did. Do you have the latest Command Line Tools installed?

Check:

/usr/bin/xcrun --sdk macosx --show-sdk-path

Then look /usr/include/expat_config.h in the shown path.


Anyway, the problem remains with older macOS versions/older Xcode. I tried to auto-detect the proper expat, but it doesn't seems to really work:


RCS file: /cvsroot/pkgsrc/textproc/expat/builtin.mk,v
retrieving revision 1.27
diff -u -r1.27 builtin.mk
--- builtin.mk 31 Jan 2026 17:39:20 -0000 1.27
+++ builtin.mk 18 Jun 2026 05:15:36 -0000
@@ -3,7 +3,7 @@
 BUILTIN_PKG:= expat
   BUILTIN_FIND_HEADERS_VAR:= H_EXPAT
-BUILTIN_FIND_HEADERS.H_EXPAT= expat.h
+BUILTIN_FIND_HEADERS.H_EXPAT= expat.h expat_config.h
   .include "../../mk/buildlink3/bsd.builtin.mk"
  


Adam