Errors Installing Composer on macOS (JIT compilation Failed)

Question

When I run composer --version in the macOS terminal I get the following errors:

PHP Warning: preg_match(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 755

Warning: preg_match(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 755
PHP Warning:  preg_match(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 759

Warning: preg_match(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 759
PHP Warning:  preg_split(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 654

Warning: preg_split(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 654
PHP Warning:  preg_split(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 1091

Warning: preg_split(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Application.php on line 1091
PHP Warning:  preg_replace(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Formatter/OutputFormatter.php on line 36

Warning: preg_replace(): JIT compilation failed: no more memory in phar:///usr/local/bin/composer.phar/vendor/symfony/console/Formatter/OutputFormatter.php on line 36

  [ErrorException]                                          
  preg_match_all(): JIT compilation failed: no more memory

Answer 1

This is a known PHP 7.3 bug, which has already been fixed.

As a temporary workaround, edit your php.ini file (in my case: vi /usr/local/etc/php/7.3/php.ini), disable PHP PCRE JIT compilation by changing:

;pcre.jit=1

to

pcre.jit=0