[PATCH v2] features_check: warn about nodistro in message

[Walter Werner SCHNEIDER <contact@schnwalter.eu>]

When a required distro feature is missing and DISTRO is set to nodistro,
provide a clear hint to the user. This helps newcomers starting projects
without a DISTRO configured who attempt to build images like
core-image-weston that depend on specific distro features.

Signed-off-by: Walter Werner SCHNEIDER <contact@schnwalter.eu>
---
v1 -> v2: Changed the error message.

As pointed out by others, the message might not be technically correct,
but I think it's good enough for new users, experienced users will know
that they can either update the DISTRO_FEATURES or use a different
DISTRO, new users will start asking question why they have "nodistro"
and wether or not that has something to do with the missing
DISTRO_FEATURES. This is how the error message used to look like:

ERROR: Nothing PROVIDES 'core-image-weston'
core-image-weston was skipped: missing required distro feature 'wayland'
(not in DISTRO_FEATURES)

And now it looks like this:

ERROR: Nothing PROVIDES 'core-image-weston'
core-image-weston was skipped: using DISTRO 'nodistro', which is missing
required DISTRO_FEATURES: 'wayland'



 meta/classes-recipe/features_check.bbclass | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/meta/classes-recipe/features_check.bbclass b/meta/classes-recipe/features_check.bbclass
index 1e0eaa4eed..36ed4fa4be 100644
--- a/meta/classes-recipe/features_check.bbclass
+++ b/meta/classes-recipe/features_check.bbclass
@@ -42,8 +42,13 @@ python () {
         if required_features:
             missing = set.difference(required_features, features)
             if missing:
-                raise bb.parse.SkipRecipe("missing required %s feature%s '%s' (not in %s_FEATURES)"
-                    % (kind.lower(), 's' if len(missing) > 1 else '', ' '.join(missing), kind))
+                if kind == 'DISTRO':
+                    raise bb.parse.SkipRecipe("using %s '%s', which is missing required %s_FEATURES: '%s'"
+                        % (kind, d.getVar(kind), kind, ' '.join(missing)))
+                else:
+                    raise bb.parse.SkipRecipe("missing required %s_FEATURES: '%s'"
+                        % (kind, ' '.join(missing)))
+
 
         conflict_features = set((d.getVar('CONFLICT_' + kind + '_FEATURES') or '').split())
         if conflict_features: