What is the configure line used? Especially i am interested if spl or sqlite are build shared. And is this a clean cvs checkout or patched somewhere? The reason i ask is that for your problem we have a mechanismn in place already.

Also what is the order of 'phpext_spl_ptr' and 
'phpext_sqlite_ptr' in main/internal_functions_*.c's 'php_builtin_extensions' array?

Both SPL and SQLite were built statically into the PHP      
binary. I was using an unpatched daily snapshot (from     
http://snaps.php.net/php5-latest.tar.bz2). The ./configure     
line was:       
       
./configure --without-mime-magic --enable-memory-limit       
--disable-debug --with-layout=GNU       
--with-pear=/usr/share/php --enable-calendar       
--enable-sysvsem --enable-sysvshm --enable-sysvmsg       
--enable-track-vars --enable-trans-sid --enable-bcmath       
--with-bz2 --enable-ctype --with-db4 --with-iconv       
--enable-exif --enable-filepro --enable-ftp --with-gettext       
--enable-mbstring --with-pcre-regex=/usr --enable-shmop       
--enable-sockets --enable-wddx --disable-xml       
--with-expat-dir=/usr --with-xmlrpc --enable-yp       
--with-zlib --with-pgsql=/usr --with-kerberos       
--with-openssl=/usr --with-exec-dir=/usr/lib/php5/libexec       
--prefix=/usr --with-apxs2=/usr/bin/apxs2 --with-regex=php       
--with-config-file-path=/etc/php5/apache2 --disable-rpath       
--with-curl=/usr --with-dom=/usr --with-dom-xslt=/usr       
--with-dom-exslt=/usr --with-zlib-dir=/usr --with-gd=/usr       
--enable-gd-native-ttf --with-jpeg-dir=/usr       
--with-xpm-dir=/usr/X11R6 --with-png-dir=/usr       
--with-freetype-dir=/usr --with-imap=/usr --with-imap-ssl       
--with-mcal=/usr --with-mhash=/usr --without-mm       
--with-mysql=/usr --with-mysqli=/usr/bin/mysql_config       
--with-unixODBC=/usr --enable-xslt=/usr       
--with-xslt-sablot=/usr --with-snmp=/usr       
--without-sybase-ct --with-ttf=/usr --with-t1lib=/usr       
--without-custom-odbc --without-odbc --without-unixODBC       
--without-iodbc --with-sqlite=/usr       
     
And here's how they're ordered in the snapshot sources:     
       
zend_module_entry *php_builtin_extensions[] = {     
        phpext_xmlrpc_ptr,     
        phpext_xml_ptr,     
        phpext_wddx_ptr,     
        phpext_tokenizer_ptr,     
        phpext_sysvshm_ptr,     
        phpext_sysvsem_ptr,     
        phpext_sysvmsg_ptr,     
        phpext_standard_ptr,     
        phpext_sqlite_ptr,     
        phpext_spl_ptr,     
        phpext_sockets_ptr,     
        phpext_snmp_ptr,     
        phpext_simplexml_ptr,     
        phpext_shmop_ptr,     
        phpext_session_ptr,     
        phpext_posix_ptr,     
        phpext_pgsql_ptr,     
        phpext_pcre_ptr,     
        phpext_mysqli_ptr,     
        phpext_mysql_ptr,     
        phpext_mhash_ptr,     
        phpext_mbstring_ptr,     
        phpext_imap_ptr,     
        phpext_iconv_ptr,     
        phpext_gettext_ptr,     
        phpext_gd_ptr,     
        phpext_ftp_ptr,     
        phpext_filepro_ptr,     
        phpext_exif_ptr,     
        phpext_dom_ptr,     
        phpext_dba_ptr,     
        phpext_curl_ptr,     
        phpext_ctype_ptr,     
        phpext_calendar_ptr,     
        phpext_bz2_ptr,     
        phpext_bcmath_ptr,     
        phpext_zlib_ptr,     
        phpext_openssl_ptr,     
        phpext_libxml_ptr,     
};     
    
Without the patch I submitted, moving phpext_spl_ptr back    
or forward in that list did prevent PHP from segfaulting.    
   
After doubled-checking with GDB, it appeared that the SPL  
startup function (zm_startup_spl) was not being called at  
all. 
 
So, I stuck a manual call to PHP_MINIT(spl) in 
basic_functions.c because it seemed the most logical place  
for this.

Oops -- I meant to say:  
 
Moving phpext_sqlite_ptr and phpext_spl_ptr around in that 
list did _not_ prevent a segfault. 
 
Sorry. :)

You need to install gawk and rebuild. Please verify (for me it helped).

Replacing mawk with gawk solved the problem.

Many thanks.

The extension loading system is now fixed, it does not make any difference what AWK version is used anymore (HEAD).