You get a warning:
PHP Warning: Xdebug MUST be loaded as a Zend extension in Unknown on line 0

Please load xdebug with zend_extension like is written in the documentation.

i thank for answer but i testing :

zend_extension and extension for include : xdebug

it's same !!!

see the trace with this ligne :

glibc detected php: free(): invalid pointer: 0xb64be410 ***
======= Backtrace: =========
/lib/i686/cmov/libc.so.6(+0x6b281)[0xb711c281]
/lib/i686/cmov/libc.so.6(+0x6cad8)[0xb711dad8]
/lib/i686/cmov/libc.so.6(cfree+0x6d)[0xb7120bbd]
/usr/local/apache2/modules/xdebug.so(zm_activate_xdebug+0x1af)[0xb6b27cac]
php[0x838c4a1]
php(zend_hash_apply+0x3f)[0x839283f]
php[0x838744a]
php(php_request_startup+0xe5)[0x83363f5]
php[0x8407175]
/lib/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0xb70c7c76]
php[0x806ceb1]
======= Memory map: ========
08048000-08875000 r-xp 00000000 08:01 600926 /usr/local/bin/php
08875000-0887d000 rw-p 0082d000 08:01 600926 /usr/local/bin/php
0887d000-0889b000 rw-p 00000000 00:00 0
08f8c000-08fad000 rw-p 00000000 00:00 0 [heap]
b639d000-b63ba000 r-xp 00000000 08:01 1032195 /lib/libgcc_s.so.1
b63ba000-b63bb000 rw-p 0001c000 08:01 1032195 /lib/libgcc_s.so.1
b63c2000-b6589000 rwxp 00000000 00:00 0
b6589000-b6593000 r-xp 00000000 08:01 1049115 /lib/i686/cmov/libnss_files-2.11.2.so
b6593000-b6594000 r--p 00009000 08:01 1049115 /lib/i686/cmov/libnss_files-2.11.2.so
b6594000-b6595000 rw-p 0000a000 08:01 1049115 /lib/i686/cmov/libnss_files-2.11.2.so
b6595000-b664a000 rwxp 00000000 00:00 0
b664a000-b6656000 r-xp 00000000 08:01 1949697 /usr/lib/libgomp.so.1.0.0
b6656000-b6657000 rw-p 0000b000 08:01 1949697 /usr/lib/libgomp.so.1.0.0
b6657000-b6676000 r-xp 00000000 08:01 1949807 /usr/lib/libjpeg.so.62.0.0
b6676000-b6677000 rw-p 0001e000 08:01 1949807 /usr/lib/libjpeg.so.62.0.0
b6677000-b667e000 rwxp 00000000 00:00 0
b667e000-b6938000 r-xp 00000000 08:01 81921 /usr/local/lib/libMagickCore.so.5.0.0
b6938000-b69da000 rw-p 002b9000 08:01 81921 /usr/local/lib/libMagickCore.so.5.0.0
b69da000-b69db000 rw-p 00000000 00:00 0
b69db000-b6ac8000 r-xp 00000000 08:01 81925 /usr/local/lib/libMagickWand.so.5.0.0
b6ac8000-b6aca000 rw-p 000ed000 08:01 81925 /usr/local/lib/libMagickWand.so.5.0.0
b6aca000-b6acb000 rwxp 00000000 00:00 0
b6acb000-b6b14000 r-xp 00000000 08:01 819395 /usr/local/lib/php/extensions/no-debug-non-zts-20090626/imagick.so
b6b14000-b6b1f000 rw-p 00048000 08:01 819395 /usr/local/lib/php/extensions/no-debug-non-zts-20090626/imagick.so
b6b1f000-b6b4e000 r-xp 00000000 08:01 641258 /usr/local/apache2/modules/xdebug.so
b6b4e000-b6b50000 rw-p 0002f000 08:01 641258 /usr/local/apache2/modules/xdebug.so
b6b50000-b6bf4000 rwxp 00000000 00:00 0
b6bf4000-b6c08000 rwxp 00000000 00:00 0
b6c08000-b6d7d000 r--p 00000000 08:01 599566 /usr/lib/locale/locale-archive
b6d7d000-b6dce000 rwxp 00000000 00:00 0
b6dce000-b6dd0000 rw-p 00000000 00:00 0
b6dd0000-b6dd3000 r-xp 00000000 08:01 584560 /usr/lib/libgpg-error.so.0.4.0
b6dd3000-b6dd4000 rw-p 00002000 08:01 584560 /usr/lib/libgpg-error.so.0.4.0
b6dd4000-b6dd5000 rw-p 00000000 00:00 0
b6dd5000-b6de4000 r-xp 00000000 08:01 584570 /usr/lib/libtasn1.so.3.1.9
b6de4000-b6de5000 rw-p 0000e000 08:01 584570 /usr/lib/libtasn1.so.3.1.9
b6de5000-b6de7000 r-xp 00000000 08:01 1033681 /lib/libkeyutils.so.1.3
b6de7000-b6de8000 rw-p 00001000 08:01 1033681 /lib/libkeyutils.so.1.3
b6de8000-b6dee000 r-xp 00000000 08:01 584473 /usr/lib/libkrb5support.so.0.1
b6dee000-b6def000 rw-p 00005000 08:01 584473 /usr/lib/libkrb5support.so.0.1
b6def000-b6df1000 r-xp 00000000 08:01 1032260 /lib/libcom_err.so.2.1
b6df1000-b6df2000 rw-p 00001000 08:01 1032260 /lib/libcom_err.so.2.1
b6df2000-b6e14000 r-xp 00000000 08:01 584475 /usr/lib/libk5crypto.so.3.1
b6e14000-b6e15000 rw-p 00022000 08:01 584475 /usr/lib/libk5crypto.so.3.1
b6e15000-b6e16000 rw-p 00000000 00:00 0
b6e16000-b6ec2000 r-xp 00000000 08:01 584477 /usr/lib/libkrb5.so.3.3
b6ec2000-b6ec8000 rw-p 000ac000 08:01 584477 /usr/lib/libkrb5.so.3.3
b6ec8000-b6ede000 r-xp 00000000 08:01 586428 /usr/lib/libsasl2.so.2.0.23
b6ede000-b6edf000 rw-p 00015000 08:01 586428 /usr/lib/libsasl2.so.2.0.23
b6edf000-b6f50000 r-xp 00000000 08:01 584568 /usr/lib/libgcrypt.so.11.5.3
b6f50000-b6f53000 rw-p 00070000 08:01 584568 /usr/lib/libgcrypt.so.11.5.3
b6f53000-b6fe7000 r-xp 00000000 08:01 584581 /usr/lib/libgnutls.so.26.14.12
b6fe7000-b6feb000 rw-p 00094000 08:01 584581 /usr/lib/libgnutls.so.26.14.12
b6feb000-b7019000 r-xp 00000000 08:01 584480 /usr/lib/libgssapi_krb5.so.2.2
b7019000-b701a000 rw-p 0002d000 08:01 584480 /usr/lib/libgssapi_krb5.so.2.2
b701a000-b701b000 rw-p 00000000 00:00 0
b701b000-b705d000 r-xp 00000000 08:01 586431 /usr/lib/libldap_r-2.4.so.2.5.6
b705d000-b705f000 rw-p 00041000 08:01 586431 /usr/lib/libldap_r-2.4.so.2.5.6
b705f000-b7060000 rw-p 00000000 00:00 0
b7060000-b706b000 r-xp 00000000 08:01 586430 /usr/lib/liblber-2.4.so.2.5.6
b706b000-b706c000 rw-p 0000a000 08:01 586430 /usr/lib/liblber-2.4.so.2.5.6
b706c000-b709c000 r-xp 00000000 08:01 586419 /usr/lib/libidn.so.11.5.44
b709c000-b709d000 rw-p 0002f000 08:01 586419 /usr/lib/libidn.so.11.5.44
b709d000-b70ad000 r-xp 00000000 08:01 1049102 /lib/i686/cmov/libresolv-2.11.2.so
b70ad000-b70ae000 r--p 00010000 08:01 1049102 /lib/i686/cmov/libresolv-2.11.2.so
b70ae000-b70af000 rw-p 00011000 08:01 1049102 /lib/i686/cmov/libresolv-2.11.2.so
b70af000-b70b1000 rw-p 00000000 00:00 0
b70b1000-b71f1000 r-xp 00000000 08:01 1049117 /lib/i686/cmov/libc-2.11.2.so
b71f1000-b71f3000 r--p 0013f000 08:01 1049117 /lib/i686/cmov/libc-2.11.2.so
b71f3000-b71f4000 rw-p 00141000 08:01 1049117 /lib/i686/cmov/libc-2.11.2.so
b71f4000-b71f8000 rw-p 00000000 00:00 0
b71f8000-b731c000 r-xp 00000000 08:01 584482 /usr/lib/libxml2.so.2.7.8
b731c000-b7321000 rw-p 00124000 08:01 584482 /usr/lib/libxml2.so.2.7.8
b7321000-b7322000 rw-p 00000000 00:00 0
b7322000-b7346000 r-xp 00000000 08:01 1049101 /lib/i686/cmov/libm-2.11.2.so
b7346000-b7347000 r--p 00023000 08:01 1049101 /lib/i686/cmov/libm-2.11.2.so
b7347000-b7348000 rw-p 00024000 08:01 1049101 /lib/i686/cmov/libm-2.11.2.so
b7348000-b735b000 r-xp 00000000 08:01 1049116 /lib/i686/cmov/libnsl-2.11.2.so
b735b000-b735c000 r--p 00012000 08:01 1049116 /lib/i686/cmov/libnsl-2.11.2.so
b735c000-b735d000 rw-p 00013000 08:01 1049116 /lib/i686/cmov/libnsl-2.11.2.so
b735d000-b735f000 rw-p 00000000 00:00 0
b735f000-b7374000 r-xp 00000000 08:01 1049106 /lib/i686/cmov/libpthread-2.11.2.so
b7374000-b7375000 r--p 00014000 08:01 1049106 /lib/i686/cmov/libpthread-2.11.2.so
b7375000-b7376000 rw-p 00015000 08:01 1049106 /lib/i686/cmov/libpthread-2.11.2.so
b7376000-b7378000 rw-p 00000000 00:00 0
b7378000-b752a000 r-xp 00000000 08:01 588566 /usr/lib/libmysqlclient.so.16.0.0
b752a000-b752e000 r--p 001b1000 08:01 588566 /usr/lib/libmysqlclient.so.16.0.0
b752e000-b7573000 rw-p 001b5000 08:01 588566 /usr/lib/libmysqlclient.so.16.0.0
b7573000-b7575000 rw-p 00000000 00:00 0
b7575000-b75c2000 r-xp 00000000 08:01 90205 /usr/lib/libcurl-gnutls.so.4.2.0
b75c2000-b75c4000 rw-p 0004c000 08:01 90205 /usr/lib/libcurl-gnutls.so.4.2.0
b75c4000-b7701000 r-xp 00000000 08:01 598091 /usr/lib/i686/cmov/libcrypto.so.0.9.8
b7701000-b7719000 rw-p 0013c000 08:01 598091 /usr/lib/i686/cmov/libcrypto.so.0.9.8Abandon

now i use : zend_extension ="/usr/local..../xdebug.so"

sorry my last trace is with : zend_extension ="/usr/local..../xdebug.so"
in my php.ini and the firts trace when i use : extension ="/usr/local..../xdebug.so"

Can you please make a backtrace like is described at : https://bugs.php.net/bugs-generating-backtrace.php

I am closing this out, as no feedback was provided.