Is it possible to disable _FILE_OFFSET_BITS==64 in CPython (as a Yocto/Poky package)?

I have a bitbake recipe with a dependency on Python2.7.

I'm trying to compile a C file (generated by CFFI) that includes both Python.h and a library header that includes fts.h somewhere down the line. It fails with

#error "<fts.h> cannot be used with -D_FILE_OFFSET_BITS==64"

I noticed that _FILE_OFFSET_BITS is set to 64 in pyconfig.h:1136, and that file is automatically generated, so I'm wondering if I can prevent this #define from being included, at the cost of not being able to access files >2GB.

For the record, Python is being included through

RDEPENDS_${PN} += "python"

in the file

/common/recipes-core/packagegroups/nativesdk-packagegroup-swi-toolchain.bb

Solution

Oh it ended up being rather simple!

files/disable-lfs.patch

--- Python-2.7.3.orig/configure.in
+++ Python-2.7.3/configure.in
@@ -1449,7 +1449,7 @@
 # structures (such as rlimit64) without declaring them. As a
 # work-around, disable LFS on such configurations

-use_lfs=yes
+use_lfs=no
 AC_MSG_CHECKING(Solaris LFS bug)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 #define _LARGEFILE_SOURCE 1

python-native_%.bbappend

FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
SRC_URI += "file://disable-lfs.patch"