Cannot update Composer's memory size - composer-php

Question

I'm trying to install an extension on Magento 2 via Composer, but when I run Composer update, I get the following error:
composer update
Loading composer repositories with package information
Updating dependencies (including require-dev)
Fatal error: Allowed memory size of 2147483648 bytes exhausted (tried to allocate 4096 bytes) in phar:///usr/local/bin/composer.phar/src/Composer/DependencyResolver/RuleWatchGraph.php on line 52
I try:
php -d memory_limit=-1 composer update
But I get:
Could not open input file: composer
So I tried and got:
curl -sS https://getcomposer.org/installer | php
All settings correct for using Composer
Downloading...
Composer (version 1.9.0) successfully installed to: /home/customer/www/xxx/public_html/composer.phar
Use it: php composer.phar
So, thinking it's fixed I again tried and got:
php -d memory_limit=-1 composer.phar install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. Run update to update them.
Nothing to install or update
Package phpunit/phpunit-mock-objects is abandoned, you should avoid using it. No replacement was suggested.
Generating autoload files
So I tried composer update again and got:
composer update
Loading composer repositories with package information
Updating dependencies (including require-dev)
Fatal error: Allowed memory size of 2147483648 bytes exhausted (tried to allocate 4096 bytes) in phar:///usr/local/bin/composer.phar/src/Composer/DependencyResolver/RuleWatchGraph.php on line 52
So again, I try composer update and get
Could not open input file: composer
I'm right back to where I started and incredibly confused :/ Please advise. Thank you.

Answer 1

When you are using php -d memory_limit=-1 you are setting an ini entry on the fly but only for the script run via that command.
Your idea to run this command was close to what you want to achieve:
php -d memory_limit=-1 composer update
The only thing you have to know is the fact that composer works as a command because it stands somewhere your OS would look for all the executables (most likely /usr/bin/composer, /usr/local/bin/composer, or something the like, this is usually referenced as the PATH). But when you try to run php composer, then composer is just considered as a regular file, and your OS do not try to look in your executable path anymore.
What you can do still is to use the command which, that will return you the path to that composer executable.
$ php $(which composer) -V
Composer version 1.8.6 2019-06-11 15:03:05
So you should be able to achieve what you aim to do via
php -d memory_limit=-1 $(which composer) install
for installation of packages; and
php -d memory_limit=-1 $(which composer) update
for updates.
Please also mind that: there is a full article in the composer documentation about memory limit: https://getcomposer.org/doc/articles/troubleshooting.md#memory-limit-errors
That could possibly ease you job, changing the relevant PHP CLI setting, or that could point you at the usage of
COMPOSER_MEMORY_LIMIT=-1 composer install
and
COMPOSER_MEMORY_LIMIT=-1 composer update