php can't find zend extensions

Hi, I was trying to set up ioncube loader on my servers. On one of them all went well. I've got php-5.6 there. On the other one, running php-5.4, it couldn't find the *.so file. As far as I can tell, php doesn't look into /usr/lib/php5 directory there: $ strace php --version ... access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/tls/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/x86_64-linux-gnu/tls/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/tls/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/x86_64-linux-gnu/tls", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/x86_64-linux-gnu/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/x86_64-linux-gnu", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0 open("/usr/lib/x86_64-linux-gnu/tls/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/x86_64-linux-gnu/tls/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/usr/lib/x86_64-linux-gnu/tls/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/x86_64-linux-gnu/tls", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/usr/lib/x86_64-linux-gnu/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/x86_64-linux-gnu/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/usr/lib/x86_64-linux-gnu/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/x86_64-linux-gnu", {st_mode=S_IFDIR|0755, st_size=20480, ...}) = 0 open("/lib/tls/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/tls/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/lib/tls/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/tls", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/lib/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/lib/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/lib", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0 open("/usr/lib/tls/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/tls/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/usr/lib/tls/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/tls", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/usr/lib/x86_64/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib/x86_64", 0x7fff2cc8cf60) = -1 ENOENT (No such file or directory) open("/usr/lib/ioncube_loader_lin_5.4.so", O_RDONLY) = -1 ENOENT (No such file or directory) stat("/usr/lib", {st_mode=S_IFDIR|0755, st_size=12288, ...}) = 0 munmap(0x7f1f3e188000, 37265) = 0 write(2, "Failed loading ioncube_loader_li"..., 128Failed loading ioncube_loader_lin_5.4.so: ioncube_loader_lin_5.4.so: cannot open shared object file: No such file or directory ) = 128 open("/usr/lib/php5/20100525/mysqlnd.so", O_RDONLY) = 6 ... As opposed to the php-5.6 server: $ strace php --version ... futex(0x7fbf391860c8, FUTEX_WAKE_PRIVATE, 2147483647) = 0 open("/usr/lib/php5/20131226/ioncube_loader_lin_5.6.so", O_RDONLY|O_CLOEXEC) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220o\2\0\0\0\0\0"..., 832) = 832 ... More details can be found here: http://unix.stackexchange.com/questions/200602/php-cant-find-zend-extension-ioncube/201719 Was there some change in the way zend extensions are handled? Is it governed by some configure options? Can I find out what options were specified when building the package? Where am I supposed to put them for php-5.4 or older? Should I specify full path? I'm running debian 8 (php-5.6) and debian 7 (php-5.4) on the servers. Regards, Yuri