Can't open subdirectory of /tmp or /var/tmp

[jennik]

I faced this problem while using xhprof and php-fpm on centos 7.

If you use php-fpm daemon configured to use private tmp directory (set to true by default in centos 7) and set xhprof.output_dir as subdirectory of /tmp, you probably notice than reports files can't be saved to that dir.
In that case you get the following message: "PHP Warning: fopen(/tmp/xhprof/58ed54f13807d.xhprof_testing.xhprof): failed to open stream: No such file or directory in /usr/share/pear/xhprof_lib/utils/xhprof_runs.php on line 136".
This happens because of php-fpm service cleans up /tmp directory each time the service started/restarted. So you have to create all subdirectories into /tmp each time you restart php-fpm.

Example:

$ cat /etc/php.d/xhprof.ini 
[xhprof]
extension=xhprof.so
xhprof.output_dir="/tmp/xhprof"

$ cat /usr/lib/systemd/system/php-fpm.service | grep PrivateTmp
PrivateTmp=true

$ sudo ls /tmp/systemd-private-b5096469cfb44152913c896b78570a6d-php-fpm.service-lP5PdF/tmp/xhprof
58f35870bd648.xhprof_testing.xhprof

$ sudo systemctl restart php-fpm

$ sudo ls /tmp/systemd-private-b5096469cfb44152913c896b78570a6d-php-fpm.service-EqBde7/tmp/xhprof
ls: cannot access /tmp/systemd-private-b5096469cfb44152913c896b78570a6d-php-fpm.service-EqBde7/tmp/xhprof: No such file or directory