Unable to generate API definitions for spring using OpenApi 3.0 spec

Description

Unable to generate API definitions for spring using OpenApi 3.0 spec

Swagger-codegen version

3.0

Swagger declaration file content or url

Command line used for generation

Steps to reproduce

Here are contents of my pom file

Pom.xml

   `<plugin>
	   <groupId>io.swagger</groupId>
	   <artifactId>swagger-codegen-maven-plugin</artifactId>
	   <version>3.0.0-rc0</version>
	   <executions>
	      <execution>
	         <goals>
	            <goal>generate</goal>
	         </goals>
	         <configuration>
	            <environmentVariables>
	               <models />
	            </environmentVariables>
	            <inputSpec>${project.basedir}/src/main/resources/user-service.yaml</inputSpec>
	            <language>spring</language>
	            <output>${project.build.directory}/generated-sources/openapi</output>
	            <modelPackage>com.example.userservice.generated.openapi.model</modelPackage>
	            <apiPackage>com.example.userservice.generated.openapi.api</apiPackage>
	            <configOptions>
	               <interfaceOnly>true</interfaceOnly>
	               <skipOverwrite>true</skipOverwrite>
	            </configOptions>
	         </configuration>
	      </execution>
	   </executions>
	   <dependencies>
			<dependency>
				<groupId>io.swagger</groupId>
				<artifactId>swagger-codegen-generators</artifactId>
				<version>1.0.0-rc1</version>
			</dependency>
		</dependencies>
	</plugin>`

Yaml file used

https://raw.githubusercontent.com/OAI/OpenAPI-Specification/master/examples/v3.0/petstore.yaml

mvn clean install

[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for com.example:user-service🫙0.0.1-SNAPSHOT
[WARNING] 'dependencies.dependency.(groupId:artifactId:type:classifier)' must be unique: org.springframework.boot:spring-boot-starter-web:jar -> duplicate declaration of version (?) @ line 54, column 23
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
[INFO]
[INFO] -----------------------< com.example:user-service >-----------------------
[INFO] Building user-service 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[WARNING] The POM for org.apache.httpcomponents:httpcore🫙4.4.9 is invalid, transitive dependencies (if any) will not be available, enable debug logging for more details
[INFO]
[INFO] --- maven-clean-plugin:3.0.0:clean (default-clean) @ user-service ---
[INFO] Deleting /home/test/project/example/user-service/target
[INFO]
[INFO] --- swagger-codegen-maven-plugin:3.0.0-rc1:generate (default) @ user-service ---
Downloading from central: https://repo.maven.apache.org/maven2/io/swagger/swagger-models/1.5.19/swagger-models-1.5.19.jar
Downloading from central: https://repo.maven.apache.org/maven2/io/swagger/swagger-annotations/1.5.19/swagger-annotations-1.5.19.jar
Downloaded from central: https://repo.maven.apache.org/maven2/io/swagger/swagger-annotations/1.5.19/swagger-annotations-1.5.19.jar (22 kB at 70 kB/s)
Downloaded from central: https://repo.maven.apache.org/maven2/io/swagger/swagger-models/1.5.19/swagger-models-1.5.19.jar (151 kB at 327 kB/s)
[WARNING] Output directory does not exist, or is inaccessible. No file (.swagger-codegen-ignore) will be evaluated.
[INFO] Invoker Package Name, originally not set, is now dervied from api package name: com.example.userservice.generated.openapi
[WARNING] String to be sanitized is null. Default to Object
[WARNING] String to be sanitized is null. Default to Object
[INFO] writing file /home/test/project/example/user-service/target/generated-sources/openapi/src/main/java/com/example/userservice/generated/openapi/model/Error.java
[INFO] writing file /home/test/project/example/user-service/target/generated-sources/openapi/src/main/java/com/example/userservice/generated/openapi/model/Pet.java
[INFO] writing file /home/test/project/example/user-service/target/generated-sources/openapi/src/main/java/com/example/userservice/generated/openapi/model/Pets.java
[ERROR]
java.lang.RuntimeException: Could not generate api file for 'pets'
at io.swagger.codegen.DefaultGenerator.generateApis (DefaultGenerator.java:527)
at io.swagger.codegen.DefaultGenerator.generate (DefaultGenerator.java:731)
at io.swagger.codegen.plugin.CodeGenMojo.execute (CodeGenMojo.java:534)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:498)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
Caused by: com.github.jknack.handlebars.HandlebarsException: /v2/JavaSpring/api.mustache💯54: java.lang.ClassCastException: java.util.HashMap cannot be cast to io.swagger.codegen.VendorExtendable
/v2/JavaSpring/api.mustache💯54
at io.swagger.codegen.handlebars.helpers.ExtensionHelper.apply (ExtensionHelper.java:11)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.helper.EachHelper.apply (EachHelper.java:72)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.Options.fn (Options.java:433)
at io.swagger.codegen.handlebars.helpers.ExtensionHelper.apply (ExtensionHelper.java:29)
at io.swagger.codegen.handlebars.helpers.ExtensionHelper.apply (ExtensionHelper.java:11)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.Options.fn (Options.java:433)
at com.github.jknack.handlebars.helper.UnlessHelper.apply (UnlessHelper.java:50)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.helper.EachHelper.apply (EachHelper.java:72)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.Options.fn (Options.java:445)
at com.github.jknack.handlebars.helper.WithHelper.apply (WithHelper.java:58)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.internal.ForwardingTemplate.apply (ForwardingTemplate.java:72)
at io.swagger.codegen.DefaultGenerator.processTemplateToFile (DefaultGenerator.java:745)
at io.swagger.codegen.DefaultGenerator.generateApis (DefaultGenerator.java:486)
at io.swagger.codegen.DefaultGenerator.generate (DefaultGenerator.java:731)
at io.swagger.codegen.plugin.CodeGenMojo.execute (CodeGenMojo.java:534)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:498)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
Caused by: java.lang.ClassCastException: java.util.HashMap cannot be cast to io.swagger.codegen.VendorExtendable
at io.swagger.codegen.handlebars.helpers.ExtensionHelper.apply (ExtensionHelper.java:11)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.helper.EachHelper.apply (EachHelper.java:72)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.Options.fn (Options.java:433)
at io.swagger.codegen.handlebars.helpers.ExtensionHelper.apply (ExtensionHelper.java:29)
at io.swagger.codegen.handlebars.helpers.ExtensionHelper.apply (ExtensionHelper.java:11)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.Options.fn (Options.java:433)
at com.github.jknack.handlebars.helper.UnlessHelper.apply (UnlessHelper.java:50)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.helper.EachHelper.apply (EachHelper.java:72)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.Options.apply (Options.java:538)
at com.github.jknack.handlebars.Options.fn (Options.java:445)
at com.github.jknack.handlebars.helper.WithHelper.apply (WithHelper.java:58)
at com.github.jknack.handlebars.internal.Block.merge (Block.java:211)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.TemplateList.merge (TemplateList.java:95)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:130)
at com.github.jknack.handlebars.internal.BaseTemplate.apply (BaseTemplate.java:118)
at com.github.jknack.handlebars.internal.ForwardingTemplate.apply (ForwardingTemplate.java:72)
at io.swagger.codegen.DefaultGenerator.processTemplateToFile (DefaultGenerator.java:745)
at io.swagger.codegen.DefaultGenerator.generateApis (DefaultGenerator.java:486)
at io.swagger.codegen.DefaultGenerator.generate (DefaultGenerator.java:731)
at io.swagger.codegen.plugin.CodeGenMojo.execute (CodeGenMojo.java:534)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:137)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:208)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:154)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:146)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:498)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.145 s
[INFO] Finished at: 2018-05-29T13:55:15-04:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal io.swagger:swagger-codegen-maven-plugin:3.0.0-rc1:generate (default) on project user-service: Code generation failed. See above for the full exception. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

Related issues/PRs

https://github.com/swagger-api/swagger-codegen/issues/7919