From 8c0ecf733768ad651d4e50c1f58af51521971d6c Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Wed, 17 Jun 2020 16:41:33 +0200
Subject: [PATCH] Clarify why a dev tag was ignored, fixes #8951

---
 src/Composer/Repository/VcsRepository.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Composer/Repository/VcsRepository.php b/src/Composer/Repository/VcsRepository.php
index dd3aa83d1..be8ed7782 100644
--- a/src/Composer/Repository/VcsRepository.php
+++ b/src/Composer/Repository/VcsRepository.php
@@ -219,7 +219,11 @@ class VcsRepository extends ArrayRepository implements ConfigurableRepositoryInt
                 // broken package, version doesn't match tag
                 if ($data['version_normalized'] !== $parsedTag) {
                     if ($isVeryVerbose) {
-                        $this->io->writeError('<warning>Skipped tag '.$tag.', tag ('.$parsedTag.') does not match version ('.$data['version_normalized'].') in composer.json</warning>');
+                        if (preg_match('{(^dev-|[.-]?dev$)}i', $parsedTag)) {
+                            $this->io->writeError('<warning>Skipped tag '.$tag.', invalid tag name, tags can not use dev prefixes or suffixes</warning>');
+                        } else {
+                            $this->io->writeError('<warning>Skipped tag '.$tag.', tag ('.$parsedTag.') does not match version ('.$data['version_normalized'].') in composer.json</warning>');
+                        }
                     }
                     continue;
                 }