Description:
------------
# php -v
[cb,WARN] (pcbc/ext L:425) igbinary serializer is not found
PHP 7.2.4-1+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Apr  5 2018 08:53:57) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.4-1+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies

===========
couchbase support => enabled
extension version => 2.4.5
libcouchbase runtime version => 2.8.6 (git: eac059bc29f7ee60721de86a3b0e0fcec74b021b)
libcouchbase headers version => 2.8.5 (git: e9c46be209881f7a8c583523a7a58a2dbd88c110)
igbinary transcoder => disabled (install pecl/igbinary and rebuild pecl/couchbase)
zlib compressor => enabled

Directive => Local Value => Master Value
couchbase.decoder.json_arrays => 0 => 0
couchbase.encoder.compression => off => off
couchbase.encoder.compression_factor => 0.0 => 0.0
couchbase.encoder.compression_threshold => 0 => 0
couchbase.encoder.format => json => json
couchbase.log_level => WARN => WARN
couchbase.pool.max_idle_time_sec => 60 => 60

===================
# gdb /usr/sbin/php-fpm7.2 /tmp/core-php-fpm7.2.51646
GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /usr/sbin/php-fpm7.2...Reading symbols from /usr/lib/debug/.build-id/0f/23263e3254185c7819e503b20e7e8f134c73f5.debug...done.
done.
[New LWP 51646]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `php-fpm: pool mobile.bitterstrawberry.org                                    '.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007ff52e48d70d in basic_encoder_v1 (value=<optimized out>, sertype=<optimized out>, cmprtype=0, cmprthresh=0, cmprfactor=0, return_value=return_value@entry=0x7ffc57a3d3c0) at /tmp/pear/temp/couchbase/couchbase.c:530
530     /tmp/pear/temp/couchbase/couchbase.c: No such file or directory.
(gdb) bt
#0  0x00007ff52e48d70d in basic_encoder_v1 (value=<optimized out>, sertype=<optimized out>, cmprtype=0, cmprthresh=0, cmprfactor=0, return_value=return_value@entry=0x7ffc57a3d3c0) at /tmp/pear/temp/couchbase/couchbase.c:530
#1  0x00007ff52e48db19 in zif_defaultEncoder (execute_data=<optimized out>, return_value=0x7ffc57a3d3c0) at /tmp/pear/temp/couchbase/couchbase.c:954
#2  0x000055deceb90151 in zend_call_function (fci=fci@entry=0x7ffc57a3d360, fci_cache=0x7ffc57a3d290, fci_cache@entry=0x0) at /build/php7.2-I4OTpW/php7.2-7.2.4/Zend/zend_execute_API.c:833
#3  0x000055deceb90695 in _call_user_function_ex (object=object@entry=0x0, function_name=function_name@entry=0x7ff53be7f3f8, retval_ptr=retval_ptr@entry=0x7ffc57a3d3c0, param_count=param_count@entry=1, params=<optimized out>,
    no_separation=no_separation@entry=1) at /build/php7.2-I4OTpW/php7.2-7.2.4/Zend/zend_execute_API.c:654
#4  0x00007ff52e4bbe37 in pcbc_encode_value (bucket=bucket@entry=0x7ff53be7f3f0, value=<optimized out>, bytes=bytes@entry=0x7ffc57a3d488, nbytes=nbytes@entry=0x7ffc57a3d4a0, flags=flags@entry=0x7ffc57a3d508,
    datatype=datatype@entry=0x7ffc57a3d50c "") at /tmp/pear/temp/couchbase/transcoding.c:52
#5  0x00007ff52e49a854 in zim_Bucket_upsert (execute_data=<optimized out>, return_value=0x7ff53be1c720) at /tmp/pear/temp/couchbase/src/couchbase/bucket/store.c:264
#6  0x000055decec51e16 in ZEND_DO_FCALL_SPEC_RETVAL_USED_HANDLER () at /build/php7.2-I4OTpW/php7.2-7.2.4/Zend/zend_vm_execute.h:1032
#7  execute_ex (ex=0x7ff53be00040) at /build/php7.2-I4OTpW/php7.2-7.2.4/Zend/zend_vm_execute.h:59752
#8  0x000055decec520de in zend_execute (op_array=0x7ff53be701c0, op_array@entry=0x7ff5271fe878, return_value=0x0, return_value@entry=0x7ff53be1c680) at /build/php7.2-I4OTpW/php7.2-7.2.4/Zend/zend_vm_execute.h:63760
#9  0x000055deceba0973 in zend_execute_scripts (type=type@entry=8, retval=0x7ff53be1c680, retval@entry=0x0, file_count=file_count@entry=3) at /build/php7.2-I4OTpW/php7.2-7.2.4/Zend/zend.c:1496
#10 0x000055deceb3bbc0 in php_execute_script (primary_file=0x7ffc57a3fd80) at /build/php7.2-I4OTpW/php7.2-7.2.4/main/main.c:2590
#11 0x000055dece9f2dd9 in main (argc=<optimized out>, argv=<optimized out>) at /build/php7.2-I4OTpW/php7.2-7.2.4/sapi/fpm/fpm/fpm_main.c:1966