Hi,

Running "composer install" with the following composer.json ends up in
a segmentation fault.

---------- START -----------
{
    "require": {
        "propel/propel": "~2.0@dev"
    },
    "config": {
        "optimize-autoloader": true
    }
}
---------- END -------------

(*) Note: when "optimize-autoloader" is set to false the error doesn't occur.

Attached are the segfault core dump file (I didn't edit the stack
trace, it's empty) + cygcheck.out (with sensitive data edited out).

I tested the following cases:
- PHP 7.0.18
- PHP 7.0.19
- PHP 5.6.10.
- After rebase all
- After a reinstall (setup -> category view -> all -> reinstall)
- After a fresh cygwin 32-bit install in an empty directory (this is
the version I run with for years)
- After a fresh cygwin 64-bit install in an empty directory

My reason for thinking this is a cygwin issue is that this behavior
doesn't repeat under Ubuntu distros, both running in a VirtualBox VM
and via Bash/WSL (a.k.a.: Bash on Ubuntu on Windows).

Would love to hear of a fix/workaround for this issue.

Thanks.