A segmentation fault (segfault) occurs when software does something critically wrong. In the case of PHP, it means something has gone horribly wrong and your application won't run.
One common cause of PHP segmentation faults is when two extensions conflict.
Blackfire's Probe may conflict with other PHP extensions. See the "Known incompatibilities" section of our installation docs. You will find a list of extensions that often conflict with Blackfire.
If you have any of these extensions listed installed, disable them completely. If your application runs correctly, you will have uncovered your conflict. You'll need to disable the conflicting extension in order to use Blackfire.
Other times, it can be more complicated to track down the cause of a segmentation fault. The Blackfire team needs a way to reproduce the exact conditions of your environment.
If you've run into a segmentation fault, we cannot guarantee a fix for your scenario. However, there is something you can do to help.
Recreating your environment
You will need to create a portable reproduction of your segmentation fault. The team needs to see your segmentation fault from a host they have full control over. You will need to provide the team with a Vagrant box or a Docker configuration.
In short, if it is not reproducible by our team, we cannot help you. And unfortunately, even if it is reproducible, we may not be able to fix it. However, by sending us a reproducible case, you'll have a much better chance that our team can fix it.