PHP Fatal error: Allowed memory size of 1610612736 bytes exhausted (tried to allocate 67108864 bytes) in ...
If you are running into a memory_limit when using composer, there are many ways to solve the problem. Finally I'm hoping for enhancements in composer to require less memory. But until that I've found a quick solution in bash:
export COMPOSER_MEMORY_LIMIT=-1
to use before you run the composer command.
It will set the memory_limit for composer to unlimited which doesn't really mean unlimited, but the maximum allowed by the hoster. If you still get a memory_limit error afterwards, you should perhaps change your hosting provider or the hosting package to a larger one.
Other solutions can also be found here:
https://stackoverflow.com/questions/36107400/composer-update-memory-lim…