mmap() failed: [12] Cannot allocate memory PHP Fatal error: Out of memory (allocated 1646538752) (tried to allocate 20480 bytes) in /usr/share/php/Composer/DependencyResolver/GenericRule.php on line 36 code example

Example: mmap() failed: [12] Cannot allocate memory composer

/bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=1024
/sbin/mkswap /var/swap.1
/sbin/swapon /var/swap.1