src/Composer/Util/ErrorHandler.php
public static function handle($level, $message, $file, $line)
    {
        // error code is not included in error_reporting
        if (!(error_reporting() & $level)) {
            return;
        }

        if (filter_var(ini_get('xdebug.scream'), FILTER_VALIDATE_BOOLEAN)) {
            $message .= "\n\nWarning: You have xdebug.scream enabled, the warning above may be".
            "\na legitimately suppressed error that you were not supposed to see.";
        }

        if ($level !== E_DEPRECATED && $level !== E_USER_DEPRECATED) {
            throw new \ErrorException($message, 0, $level, $file, $line);
        }

        if (self::$io) {
            self::$io->writeError('<warning>Deprecation Notice: '.$message.' in '.$file.':'.$line.'</warning>');
            if (self::$io->isVerbose()) {
                self::$io->writeError('<warning>Stack trace:</warning>');
                self::$io->writeError(array_filter(array_map(function ($a) {
                    if (isset($a['line'], $a['file'])) {
                        return '<warning> '.$a['file'].':'.$a['line'].'</warning>';
                    }

                    return null;
                }, array_slice(debug_backtrace(), 2))));
            }
        }
    }
public static function handle($level, $message, $file, $line)
    {
        // error code is not included in error_reporting
        if (!(error_reporting() & $level)) {
            return;
        }

        if (filter_var(ini_get('xdebug.scream'), FILTER_VALIDATE_BOOLEAN)) {
            $message .= "\n\nWarning: You have xdebug.scream enabled, the warning above may be".
            "\na legitimately suppressed error that you were not supposed to see.";
        }

        if ($level !== E_DEPRECATED && $level !== E_USER_DEPRECATED) {
            throw new \ErrorException($message, 0, $level, $file, $line);
        }

        if (self::$io) {
            self::$io->writeError('<warning>Deprecation Notice: '.$message.' in '.$file.':'.$line.'</warning>');
            if (self::$io->isVerbose()) {
                self::$io->writeError('<warning>Stack trace:</warning>');
                self::$io->writeError(array_filter(array_map(function ($a) {
                    if (isset($a['line'], $a['file'])) {
                        return '<warning> '.$a['file'].':'.$a['line'].'</warning>';
                    }

                    return null;
                }, array_slice(debug_backtrace(), 2))));
            }
        }
    }
public static function handle ( $ level , $ message , $ file , $ line ) { // error code is not included in error_reporting if ( ! ( error_reporting ( ) & $ level ) ) { return ; } if ( filter_var ( ini_get ( 'xdebug.scream' ) , FILTER_VALIDATE_BOOLEAN ) ) { $ message .= "\n\nWarning: You have xdebug.scream enabled, the warning above may be" . "\na legitimately suppressed error that you were not supposed to see." ; } if ( $ level !== E_DEPRECATED && $ level !== E_USER_DEPRECATED ) { throw new \ ErrorException ( $ message , 0 , $ level , $ file , $ line ) ; } if ( self :: $ io ) { self :: $ io -> writeError ( '<warning>Deprecation Notice: ' . $ message . ' in ' . $ file . ':' . $ line . '</warning>' ) ; if ( self :: $ io -> isVerbose ( ) ) { self :: $ io -> writeError ( '<warning>Stack trace:</warning>' ) ; self :: $ io -> writeError ( array_filter ( array_map ( function ( $ a ) { if ( isset ( $ a [ 'line' ] , $ a [ 'file' ] ) ) { return '<warning> ' . $ a [ 'file' ] . ':' . $ a [ 'line' ] . '</warning>' ; } return null ; } , array_slice ( debug_backtrace ( ) , 2 ) ) ) ) ; } } }
Error handler

@param int    $level   Level of the error raised
@param string $message Error message
@param string $file    Filename that the error was raised in
@param int    $line    Line number the error was raised at

@static
@throws \ErrorException
Error handler