Improve error messages for required hhvm/php versions, fixes #3767

src/Composer/DependencyResolver/Pool.php

@@ -65,6 +65,11 @@ class Pool
         }
         $this->stabilityFlags = $stabilityFlags;
         $this->filterRequires = $filterRequires;
+        foreach ($filterRequires as $name => $constraint) {
+            if (preg_match(PlatformRepository::PLATFORM_PACKAGE_REGEX, $name)) {
+                unset($this->filterRequires[$name]);
+            }
+        }
     }
 
     public function setWhitelist($whitelist)

src/Composer/DependencyResolver/Problem.php

@@ -87,6 +87,19 @@ class Problem
             }
 
             if ($job && $job['cmd'] === 'install' && empty($packages)) {
+                // handle php/hhvm
+                if ($job['packageName'] === 'php' || $job['packageName'] === 'php-64bit' || $job['packageName'] === 'hhvm') {
+                    $msg = "\n    - This package requires ".$job['packageName'].$this->constraintToText($job['constraint']).' but ';
+
+                    if (defined('HHVM_VERSION')) {
+                        return $msg . 'your HHVM version does not satisfy that requirement.';
+                    } elseif ($job['packageName'] === 'hhvm') {
+                        return $msg . 'you are running this with PHP and not HHVM.';
+                    }
+
+                    return $msg . 'your PHP version does not satisfy that requirement.';
+                }
+
                 // handle php extensions
                 if (0 === stripos($job['packageName'], 'ext-')) {
                     $ext = substr($job['packageName'], 4);

src/Composer/DependencyResolver/Rule.php

@@ -217,7 +217,15 @@ class Rule
                     $targetName = $this->reasonData->getTarget();
 
                     // handle php extensions
-                    if (0 === strpos($targetName, 'ext-')) {
+                    if ($targetName === 'php' || $targetName === 'php-64bit' || $targetName === 'hhvm') {
+                        if (defined('HHVM_VERSION')) {
+                            $text .= ' -> your HHVM version does not satisfy that requirement.';
+                        } elseif ($targetName === 'hhvm') {
+                            $text .= ' -> you are running this with PHP and not HHVM.';
+                        } else {
+                            $text .= ' -> your PHP version does not satisfy that requirement.';
+                        }
+                    } elseif (0 === strpos($targetName, 'ext-')) {
                         $ext = substr($targetName, 4);
                         $error = extension_loaded($ext) ? 'has the wrong version ('.(phpversion($ext) ?: '0').') installed' : 'is missing from your system';