3 files changed, 23 insertions, 3 deletions

diff --git a/scripts/lib/devtool/__init__.py b/scripts/lib/devtool/__init__.py
index 94e3d7d4b3..20ab83f83d 100644
--- a/scripts/lib/devtool/__init__.py
+++ b/scripts/lib/devtool/__init__.py
@@ -337,3 +337,16 @@ def update_unlockedsigs(basepath, workspace, fixed_setup, extra=None):
             for pn in newunlocked:
                 f.write('    ' + pn)
             f.write('"')
+
+def check_prerelease_version(ver, operation):
+    if 'pre' in ver or 'rc' in ver:
+        logger.warning('Version "%s" looks like a pre-release version. '
+                       'If that is the case, in order to ensure that the '
+                       'version doesn\'t appear to go backwards when you '
+                       'later upgrade to the final release version, it is '
+                       'recommmended that instead you use '
+                       '<current version>+<pre-release version> e.g. if '
+                       'upgrading from 1.9 to 2.0-rc2 use "1.9+2.0-rc2". '
+                       'If you prefer not to reset and re-try, you can change '
+                       'the version after %s succeeds using "devtool rename" '
+                       'with -V/--version.' % (ver, operation))
diff --git a/scripts/lib/devtool/standard.py b/scripts/lib/devtool/standard.py
index 8e4c7f7b13..b6e532bcd3 100644
--- a/scripts/lib/devtool/standard.py
+++ b/scripts/lib/devtool/standard.py
@@ -30,7 +30,7 @@ import errno
 import glob
 import filecmp
 from collections import OrderedDict
-from devtool import exec_build_env_command, setup_tinfoil, check_workspace_recipe, use_external_build, setup_git_repo, recipe_to_append, get_bbclassextend_targets, update_unlockedsigs, DevtoolError
+from devtool import exec_build_env_command, setup_tinfoil, check_workspace_recipe, use_external_build, setup_git_repo, recipe_to_append, get_bbclassextend_targets, update_unlockedsigs, check_prerelease_version, DevtoolError
 from devtool import parse_recipe
 
 logger = logging.getLogger('devtool')
@@ -298,6 +298,8 @@ def add(args, config, basepath, workspace):
 
         _add_md5(config, recipename, appendfile)
 
+        check_prerelease_version(rd.getVar('PV'), 'devtool add')
+
         logger.info('Recipe %s has been automatically created; further editing may be required to make it fully functional' % recipefile)
 
     finally:
diff --git a/scripts/lib/devtool/upgrade.py b/scripts/lib/devtool/upgrade.py
index 441dd35bbd..ab7acd16c6 100644
--- a/scripts/lib/devtool/upgrade.py
+++ b/scripts/lib/devtool/upgrade.py
@@ -33,7 +33,7 @@ sys.path = sys.path + [devtool_path]
 
 import oe.recipeutils
 from devtool import standard
-from devtool import exec_build_env_command, setup_tinfoil, DevtoolError, parse_recipe, use_external_build, update_unlockedsigs
+from devtool import exec_build_env_command, setup_tinfoil, DevtoolError, parse_recipe, use_external_build, update_unlockedsigs, check_prerelease_version
 
 logger = logging.getLogger('devtool')
 
@@ -420,8 +420,13 @@ def upgrade(args, config, basepath, workspace):
             old_srcrev = None
         if old_srcrev and not args.srcrev:
             raise DevtoolError("Recipe specifies a SRCREV value; you must specify a new one when upgrading")
-        if rd.getVar('PV') == args.version and old_srcrev == args.srcrev:
+        old_ver = rd.getVar('PV')
+        if old_ver == args.version and old_srcrev == args.srcrev:
             raise DevtoolError("Current and upgrade versions are the same version")
+        if args.version:
+            if bb.utils.vercmp_string(args.version, old_ver) < 0:
+                logger.warning('Upgrade version %s compares as less than the current version %s. If you are using a package feed for on-target upgrades or providing this recipe for general consumption, then you should increment PE in the recipe (or if there is no current PE value set, set it to "1")' % (args.version, old_ver))
+            check_prerelease_version(args.version, 'devtool upgrade')
 
         rf = None
         try: