From be77e273623fc8b8002c752b580ce1f3157f25ae Mon Sep 17 00:00:00 2001
From: Ondrej Nosek <onosek@redhat.com>
Date: Feb 08 2021 22:05:25 +0000
Subject: Better hint when running 'prep' on detached branch


JIRA: RHELCMP-3682
Resolves: rhbz#1907964

Signed-off-by: Ondrej Nosek <onosek@redhat.com>

---

diff --git a/pyrpkg/__init__.py b/pyrpkg/__init__.py
index 52dcee3..a3f5edd 100644
--- a/pyrpkg/__init__.py
+++ b/pyrpkg/__init__.py
@@ -2874,6 +2874,24 @@ class Commands(object):
 
         # setup the rpm command
         cmd = ['rpmbuild']
+
+        # When "prep" command is run on detached branch (rhbz#1907964)
+        # Recreate with: "git checkout <commit_id>".
+        # Before self.rpmdefines() executes self.load_branch_merge() and it
+        # shows potential confusing message to user,
+        # execute self.load_branch_merge() in advance and catch related
+        # exception. Set branch to value (=current commit id) that won't match
+        # any predefined branch pattern. This will lead to displaying better
+        # message to user (user is recommended to use --release argument)
+        try:
+            self.load_branch_merge()
+        except rpkgError:
+            head = self.repo.head
+            if head.is_detached:
+                self._branch_merge = head.commit.hexsha  # current commit id
+            else:
+                raise
+
         cmd.extend(self.rpmdefines)
         if builddir:
             # Tack on a new builddir to the end of the defines