I do "out of tree" builds (I think that is the right term).  I make an
empty directory, cd into it, and then do: 

<path to src directory>/configure

followed by make.  This works on most open source pages.  It appears to
be very close to working with Python 2.7.1 but the problem is that it assumes ld_so_aix is in the source tree but it is in the build tree.

I did an "in tree" build using basically just ./configure && make and so far (I'm still testing) that has worked fine.

There are some unit tests concerning distutils which are currently failing on AIX and may be an illustration of the same problem:

======================================================================
ERROR: test_build_ext (distutils.tests.test_build_ext.BuildExtTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/unixccompiler.py", line 254, in link
    self.spawn(linker + ld_args)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/ccompiler.py", line 911, in spawn
    spawn(cmd, dry_run=self.dry_run)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/spawn.py", line 34, in spawn
    _spawn_posix(cmd, search_path, dry_run=dry_run)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/spawn.py", line 138, in _spawn_posix
    % (cmd[0], exit_status))
distutils.errors.DistutilsExecError: command './Modules/ld_so_aix' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/tests/test_build_ext.py", line 85, in test_build_ext
    cmd.run()
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/command/build_ext.py", line 347, in run
    self.build_extensions()
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/command/build_ext.py", line 456, in build_extensions
    self.build_extension(ext)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/command/build_ext.py", line 543, in build_extension
    target_lang=language)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/ccompiler.py", line 719, in link_shared_object
    extra_preargs, extra_postargs, build_temp, target_lang)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/unixccompiler.py", line 256, in link
    raise LinkError(msg)
distutils.errors.LinkError: command './Modules/ld_so_aix' failed with exit status 1

======================================================================
ERROR: test_get_outputs (distutils.tests.test_build_ext.BuildExtTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/unixccompiler.py", line 254, in link
    self.spawn(linker + ld_args)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/ccompiler.py", line 911, in spawn
    spawn(cmd, dry_run=self.dry_run)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/spawn.py", line 34, in spawn
    _spawn_posix(cmd, search_path, dry_run=dry_run)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/spawn.py", line 138, in _spawn_posix
    % (cmd[0], exit_status))
distutils.errors.DistutilsExecError: command './Modules/ld_so_aix' failed with exit status 1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/tests/test_build_ext.py", line 343, in test_get_outputs
    cmd.run()
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/command/build_ext.py", line 347, in run
    self.build_extensions()
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/command/build_ext.py", line 456, in build_extensions
    self.build_extension(ext)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/command/build_ext.py", line 543, in build_extension
    target_lang=language)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/ccompiler.py", line 719, in link_shared_object
    extra_preargs, extra_postargs, build_temp, target_lang)
  File "/san_cis/home/cis/.buildbot/python-aix6/py3k-aix6-xlc/build/Lib/distutils/unixccompiler.py", line 256, in link
    raise LinkError(msg)
distutils.errors.LinkError: command './Modules/ld_so_aix' failed with exit status 1

I will take a look.

I tried with trunk (python 3.2) on AIX:
./build/configure --with-pydebug --without-computed-gotos
make
and that worked correctly.

Not sure with python 2.7.

I have experienced the same problem under ppc64 aix 6.1.2.0 while compiling Python 2.7.1

$ cd Python-2.7.1
$ mkdir __build
$ cd __build
$ ../configure --with-gcc=xlc_r --with-cxx-main=xlC_r --with-threads --disable-ipv6
$ /usr/linux/bin/make
[...]
../Modules/ld_so_aix xlc_r -bI:Modules/python.exp -L.. -L/opt/freeware/lib -L/opt/freeware/lib build/temp.aix-6.1-2.7/data/tcarel/ngbuilder/python/2.7.1/Python-2.7.1/Modules/_struct.o -L/opt/freeware/lib -L/usr/local/lib -o build/lib.aix-6.1-2.7/_struct.so
unable to execute ../Modules/ld_so_aix: No such file or directory

There are references to $(srcdir)/Modules/ld_so_aix in both configure.in and Makefile.pre.in whereas ld_so_aix is created in build tree.

==================================================
diff -r f4e6e18cae4b Makefile.pre.in
--- a/Makefile.pre.in	Tue Mar 29 17:28:25 2011 -0700
+++ b/Makefile.pre.in	Thu Mar 31 13:05:45 2011 +0200
@@ -1028,7 +1028,7 @@
 		$(INSTALL_SCRIPT) $(srcdir)/Modules/makexp_aix	\
 				$(DESTDIR)$(LIBPL)/makexp_aix;		\
 		echo "$(LIBPL)/makexp_aix";			\
-		$(INSTALL_SCRIPT) $(srcdir)/Modules/ld_so_aix	\
+		$(INSTALL_SCRIPT) Modules/ld_so_aix	\
 				$(DESTDIR)$(LIBPL)/ld_so_aix;		\
 		echo "$(LIBPL)/ld_so_aix";			\
 		echo; echo "See Misc/AIX-NOTES for details.";	\
diff -r f4e6e18cae4b configure.in
--- a/configure.in	Tue Mar 29 17:28:25 2011 -0700
+++ b/configure.in	Thu Mar 31 13:05:45 2011 +0200
@@ -1778,7 +1778,7 @@
 then
 	case $ac_sys_system/$ac_sys_release in
 	AIX*)
-		BLDSHARED="\$(srcdir)/Modules/ld_so_aix \$(CC) -bI:\$(srcdir)/Modules/python.exp"
+		BLDSHARED="Modules/ld_so_aix \$(CC) -bI:Modules/python.exp -L\$(srcdir)"
 		LDSHARED="\$(BINLIBDEST)/config/ld_so_aix \$(CC) -bI:\$(BINLIBDEST)/config/python.exp"
 		;;
 	BeOS*)
==================================================

After fixing these 2 files, Modules/ld_so_aix is found and properly executed by compilation process, but then there is a new issue:

Modules/ld_so_aix xlc_r -bI:Modules/python.exp -L.. -L/opt/freeware/lib -L/opt/freeware/lib build/temp.aix-6.1-2.7/data/tcarel/Python-2.7.1/Modules/_struct.o -L/opt/freeware/lib -L/usr/local/lib -o build/lib.aix-6.1-2.7/_struct.so
Modules/ld_so_aix[183]: Modules/makexp_aix:  not found.

This time, makexp_aix is expected to be is the same directory than ld_so_aix whereas makeexp_aix remains in the source tree.

Here is a fix:

==================================================
diff -r f4e6e18cae4b Modules/ld_so_aix.in
--- a/Modules/ld_so_aix.in	Tue Mar 29 17:28:25 2011 -0700
+++ b/Modules/ld_so_aix.in	Thu Mar 31 13:01:57 2011 +0200
@@ -69,7 +69,10 @@
   echo $usage; exit 2
 fi
 
-makexp=`dirname $0`/makexp_aix
+makexp=`dirname $0`/@srcdir@/makexp_aix
+if test ! -e "$makexp" ; then
+  makeexp=makexp_aix
+fi
 
 # Check for existence of compiler.
 CC=$1; shift
==================================================

The first value fix the issue while building Python. The second will use PATH to find makeexp_aix as explained in section `SHARED LIBRARY SUPPORT' in AIX-NOTES (for building shared extension modules).

You can find a patch for 2.7 branch in attachment.

Regards
-- 
Tristan Carel
Exalead

Basically the same as Tristan's patch, with a little improvement to not rely on PATH to find makexp_aix within ld_so_aix.

Thanks!

The idea of the patches makes sense to me.

Embedding the name of whatever directory Python was built in into the installed version of Modules/ld_so_aix.in does not seem very clean to me. Is there another way of doing this? Perhaps a file copy or symlink?

Actually, why do you remove $(srcdir) for Modules/python.exp? This code was added in r88426; see <https://bugs.python.org/issue941346#msg128586>.

Modules/python.exp is generated at build-time, thus does not belong to $(srcdir).

Okay I will assume that $(srcdir) reference was just due to a mistake or bad cargo-culting then.

Will commit this soon unless anyone has a good idea to avoid embedding @abs_srcdir@.

New changeset 48526666321a by Martin Panter in branch '3.5':
Issue #10656: Fix out-of-tree building on AIX
https://hg.python.org/cpython/rev/48526666321a

New changeset 76d1f8001e27 by Martin Panter in branch '3.6':
Issue #10656: Merge AIX build fix from 3.5
https://hg.python.org/cpython/rev/76d1f8001e27

New changeset 180f046b597e by Martin Panter in branch 'default':
Issue #10656: Merge AIX build fix from 3.6
https://hg.python.org/cpython/rev/180f046b597e

New changeset ca46883fc5cf by Martin Panter in branch '2.7':
Issue #10656: Fix out-of-tree building on AIX
https://hg.python.org/cpython/rev/ca46883fc5cf