Composer update gives "cannot allocate memory" error.

[ericbae]

My php.ini memory limit is set to "-1" and I'm trying to install a RSS builder (https://github.com/thujohn/rss-l4) using Laravel 4 and I'm getting the following error. Any ideas?

Loading composer repositories with package information
Updating dependencies (including require-dev)

• Installing thujohn/rss (dev-master df80a7d)
  Downloading: 100%
  PHP Fatal error: Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory' in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php:975
  Stack trace:
  #0 [internal function]: Composer\Util\ErrorHandler::handle(2, 'proc_open(): fo...', 'phar:///usr/loc...', 975, Array)
  Added ErrorException handler. #1 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(975): proc_open('stty -a | grep ...', Array, NULL, NULL, NULL, Array)
  Edited src/Composer/Downloader/ZipDownloader.php via GitHub #2 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(853): Symfony\Component\Console\Application->getSttyColumns()
  Implement PEAR support. #3 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(818): Symfony\Component\Console\Application->getTerminalDimensions()
  Edited README.md via GitHub #4 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(752): Symfony\Component\Console\Application->getTerminalWidth()
  Edited bin/composer via GitHub #5 phar:///usr/local/bin/com in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php on line 975

Fatal error: Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory' in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php:975
Stack trace:
#0 [internal function]: Composer\Util\ErrorHandler::handle(2, 'proc_open(): fo...', 'phar:///usr/loc...', 975, Array)
#1 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(975): proc_open('stty -a | grep ...', Array, NULL, NULL, NULL, Array)
#2 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(853): Symfony\Component\Console\Application->getSttyColumns()
#3 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(818): Symfony\Component\Console\Application->getTerminalDimensions()
#4 phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php(752): Symfony\Component\Console\Application->getTerminalWidth()
#5 phar:///usr/local/bin/com in phar:///usr/local/bin/composer/vendor/symfony/console/Symfony/Component/Console/Application.php on line 975

[jannone]

+1, composer is using a lot of memory and CPU in my dev box. I had to change my VM config from 512 mb to 1 gb lately, just to run composer.

[curry684]

Uncaught exception 'ErrorException' with message 'proc_open(): fork failed - Cannot allocate memory

proc_open is not bound by PHP's memory limit configuration - it's a thin wrapper around system level calls to fork the current project. This may turn out rather unfortunate when the host process has tons of memory in use as it could indeed wipe the whole system empty, causing this error.

To my knowledge the improvements last year in the GC handling have made Composer's memory usage friendlier outside the resolver, meaning memory usage is much lower during the installation phase, so this issue has almost certainly resolved itself by now.