Problem building python 2.7 with --enable-shared

[Marten Lehmann]

Hello,

I've build python 2.7 successfully by just calling configure, make and
make install. But to use python within PostgreSQL, I need to built
python with --enable-shared.

I tried to do so (configure --enable-shared), but I see these lines
several times in the log (but compiling continues):

/usr/bin/ld: /test/python/lib/libpython2.7.a(abstract.o): relocation
R_X86_64_32 against `a local symbol' can not be used when making a
shared object; recompile with -fPIC
/test/python/lib/libpython2.7.a: could not read symbols: Bad value
collect2: ld returned 1 exit status

Later, the compiling process ends completely:

PYTHONPATH=/var/tmp/vrmd-python2-root/test/python/lib/python2.7
LD_LIBRARY_PATH=/usr/src/redhat/BUILD/Python-2.7: \
./python -Wi -tt
/var/tmp/vrmd-python2-root/test/python/lib/python2.7/compileall.py \
-d /test/python/lib/python2.7 -f \
-x
'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
/var/tmp/vrmd-python2-root/test/python/lib/python2.7
Traceback (most recent call last):
File
"/var/tmp/vrmd-python2-root/test/python/lib/python2.7/compileall.py",
line 17, in <module>
import struct
File
"/var/tmp/vrmd-python2-root/test/python/lib/python2.7/struct.py", line
1, in <module>
from _struct import *
ImportError: No module named _struct
make: *** [libinstall] Error 1

Any ideas, what I have done wrong?

Kind regards
Marten

 

[Marten Lehmann]

The strange thing is: This only happens when I'm compiling through
rpmbuild. Issuing the same commands (configure --enable-shared, make,
make install) directly on the shell works fine...

 

[Thomas Jollans]

Hello,

I've build python 2.7 successfully by just calling configure, make and
make install. But to use python within PostgreSQL, I need to built
python with --enable-shared.

I tried to do so (configure --enable-shared), but I see these lines
several times in the log (but compiling continues):

Did you start with a clean source tree? If you just reconfigured and called
make again in the source tree where you already had built Python, make will
just re-use the old object files, which would be built without -fPIC and
whatever other options are required for the shared library linking to work.

/usr/bin/ld: /test/python/lib/libpython2.7.a(abstract.o): relocation
R_X86_64_32 against `a local symbol' can not be used when making a
shared object; recompile with -fPIC
/test/python/lib/libpython2.7.a: could not read symbols: Bad value
collect2: ld returned 1 exit status

If you get this when building from a fresh source tree, I can't explain why
this might happen, but, again, starting afresh, this time adding -fPIC to the
CFLAGS, may work. But I expect that the configure script, or makefile, or
libtool, or whatever, should do this, hence my guess that maybe you're using
leftover object files.

(hint: make clean)

Later, the compiling process ends completely:

PYTHONPATH=/var/tmp/vrmd-python2-root/test/python/lib/python2.7
LD_LIBRARY_PATH=/usr/src/redhat/BUILD/Python-2.7: \
./python -Wi -tt
/var/tmp/vrmd-python2-root/test/python/lib/python2.7/compileall.py \
-d /test/python/lib/python2.7 -f \
-x
'bad_coding|badsyntax|site-packages|lib2to3/tests/data' \
/var/tmp/vrmd-python2-root/test/python/lib/python2.7
Traceback (most recent call last):
File
"/var/tmp/vrmd-python2-root/test/python/lib/python2.7/compileall.py",
line 17, in <module>
import struct
File
"/var/tmp/vrmd-python2-root/test/python/lib/python2.7/struct.py", line
1, in <module>
from _struct import *
ImportError: No module named _struct
make: *** [libinstall] Error 1

Any ideas, what I have done wrong?

Kind regards
Marten

 

[Marten Lehmann]

I digged into this one step further:

I compared the output of configure and make. For configure, there is no
change. But for make, I found out something, that I didn't expected:

When configure is called with a prefix to a location, where a valid
python installation already exists, it uses these locations for gcc,
although it shouldn't (we are about to compile a clean, brandnew python
version, so why should it include parts of an existing python
installation?).

Additionally to the default include paths

gcc [...] -I. -IInclude -I./Include -I/usr/local/include
-I/usr/src/redhat/BUILD/Python-2.7/Include
-I/usr/src/redhat/BUILD/Python-2.7 [...]

the path of the existing Python installation is added:
-I/test/python2/include

And additionally the default library paths and libs

gcc [...] -L/usr/local/lib -L. -lpython2.7 [...]

the path of the existing Python libs is added:

gcc [...9 -L/vrmd/python2/lib

So linking to python2.7 during make doesn't link to the freshly build
library, but to the existing in the system. And at least in my case,
where I'm switching from a python installation without --enabled-shared
to a new version including --enable-shared, this causes serious problems:

/usr/bin/ld: /vrmd/python2/lib/libpython2.7.a(abstract.o): relocation
R_X86_64_32 against `a local symbol' can not be used when making a
shared object; recompile with -fPIC
-/vrmd/python2/lib/libpython2.7.a: could not read symbols: Bad value
-collect2: ld returned 1 exit status

Is there any option I missed in configure or any variable that I might
set to correct this? Or should a file a bug to the python developers?
Deinstalling python before compiling or renaming the python directory is
not a good solution.

Kind regards
Marten