Merge pull request #40 from opscode/lcg/better-depsolver-error

improve depsolver error message

1 files changed, 16 insertions, 2 deletions

diff --git a/lib/chef_zero/endpoints/environment_cookbook_versions_endpoint.rb b/lib/chef_zero/endpoints/environment_cookbook_versions_endpoint.rb
index efd21a4..2e56a51 100644
--- a/lib/chef_zero/endpoints/environment_cookbook_versions_endpoint.rb
+++ b/lib/chef_zero/endpoints/environment_cookbook_versions_endpoint.rb
@@ -6,6 +6,7 @@ module ChefZero
   module Endpoints
     # /environments/NAME/cookbook_versions
     class EnvironmentCookbookVersionsEndpoint < RestBase
+
       def post(request)
         cookbook_names = list_data(request, ['cookbooks'])
 
@@ -35,7 +36,14 @@ module ChefZero
         # Depsolve!
         solved = depsolve(request, desired_versions.keys, desired_versions, environment_constraints)
         if !solved
-          return raise RestErrorResponse.new(412, "Unsolvable versions!")
+          if @last_missing_dep && !cookbook_names.include?(@last_missing_dep)
+            return raise RestErrorResponse.new(412, "No such cookbook: #{@last_missing_dep}")
+          elsif @last_constraint_failure
+            return raise RestErrorResponse.new(412, "Could not satisfy version constraints for: #{@last_constraint_failure}")
+          else
+
+            return raise RestErrorResponse.new(412, "Unsolvable versions!")
+          end
         end
 
         result = {}
@@ -47,7 +55,12 @@ module ChefZero
       end
 
       def depsolve(request, unsolved, desired_versions, environment_constraints)
-        return nil if desired_versions.values.any? { |versions| versions.empty? }
+        desired_versions.each do |cb, ver|
+          if ver.empty?
+            @last_constraint_failure = cb
+            return nil
+          end
+        end
 
         # If everything is already
         solve_for = unsolved[0]
@@ -72,6 +85,7 @@ module ChefZero
               new_unsolved = new_unsolved + [dep_name]
               # If the dep is missing, we will try other versions of the cookbook that might not have the bad dep.
               if !exists_data_dir?(request, ['cookbooks', dep_name])
+                @last_missing_dep = dep_name.to_s
                 dep_not_found = true
                 break
               end