[GRADLE-3376] Misleading error when defining a creation rule for an unknown type on a ModelMap using model DSL Created: 30/Dec/15  Updated: 25/Jan/16  Resolved: 25/Jan/16

Status: Resolved
Project: Gradle
Affects Version/s: None
Fix Version/s: 2.11-rc-1

Type: Bug
Reporter: Mark Vieira (Inactive) Assignee: Lóránt Pintér
Resolution: Fixed Votes: 0


When using the model DSL to define a creation rule on a ModelMap, Gradle returns a misleading error when the type specified is unknown. Given the example below:

interface MyManagedType {}
class MyPlugin extends RuleSource {
    void items(ModelMap<MyManagedType> items) {}

apply plugin: MyPlugin

model {
    items {

The resulting error is:

FAILURE: Build failed with an exception.

* Where:
Build file '/Users/mark/Desktop/gradle/build.gradle' line: 13

* What went wrong:
Execution failed for task ':model'.
> Exception thrown while executing model rule: items { ... } @ build.gradle line 12, column 5
   > Attempt to read a write only view of model of type 'java.lang.Object' given to rule 'items { ... } @ build.gradle line 12, column 5'

Comment by Mark Vieira (Inactive) [ 30/Dec/15 ]

This issue was first discovered by a forums user: https://discuss.gradle.org/t/rulesource-how-to-use-a-rulesource-plugin-defined-in-a-separate-build-script/13411

Comment by Lóránt Pintér [ 25/Jan/16 ]

This has been addressed in 2.11. Now the same code should print an error message similar to this:

Attempt to read property 'SomeUnknownType' from a write only view of model element 'items' given to rule 'items { ... } @ build.gradle line 11, column 17'

While this doesn't necessarily point out the exact cause of the error (most probably a typo in a name of a type), including the name of the unknown type in the error message should help figure out what the problem is.

Generated at Wed Jun 30 12:47:11 CDT 2021 using Jira 8.4.2#804003-sha1:d21414fc212e3af190e92c2d2ac41299b89402cf.