Hjdcti

I am trying to upload one module in Magento Marketplace but in technical review the Installation & Varnish Test is failed
http://prntscr.com/mr5lt5

when I view the report then I see below error.
http://prntscr.com/mr5mgg

Environment: PHP 5.6.37 Magento 2.1 CE

composer require insider/module-integration:1.0.0 2>&1

./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 1 install, 0 updates, 0 removals

proc_open(): fork failed - Cannot allocate memory
The archive may contain identical file names with different capitalization (which fails on case insensitive filesystems)
Unzip with unzip command failed, falling back to ZipArchive class

The following exception is caused by a lack of memory or swap, or not having swap configured
Check https://getcomposer.org/doc/articles/troubleshooting.md#proc-open-fork-failed-errors for details

PHP Warning: proc_open(): fork failed - Cannot allocate memory in phar:///usr/bin/composer/vendor/symfony/console/Application.php on line 959

Warning: proc_open(): fork failed - Cannot allocate memory in phar:///usr/bin/composer/vendor/symfony/console/Application.php on line 959

[ErrorException] 
proc_open(): fork failed - Cannot allocate memory 

How can I solve this error ?

there are two possibility here

1. Looks like you runs out of swap memory,
   try this

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

/sbin/mkswap /var/swap.1

/sbin/swapon /var/swap.1

this solution was described in here

2. 
   

   A bit old but just in case someone new is looking for a solution, updating your PHP version can fix the issue.

   
   
   

   Also you should be committing your composer.lock file and doing a composer
   install on a production environment which is less resource intensive.

   
   

More details here: