If you are using Groovy, it's likely that you unintentionally added the `private` modifier to a property declaration:

```groovy
@InputFile
RegularFileProperty inputFile // this is a public property

@InputFile
private RegularFileProperty inputFile // this is a field, remove the `private` modifier
```

[[ignored_annotations_on_method]]
== Invalid annotation on method

                if (project.findProperty("inputFile")) {
                    input = file(project.property("inputFile"))
                }
            }
        """

        file("input").createDir()

        expect:
        succeeds("myTask")

        when:
        file("inputFile").createDir()
        file("inputFile/someContents.txt").text = "input"

        0 * _
    }

    static class MyTask extends DefaultTask {

        @Input
        String myProperty = "myValue"

        @InputFile
        @PathSensitive(PathSensitivity.NONE)
        File inputFile = new File("some-location")

        @InputFiles
        @PathSensitive(PathSensitivity.NONE)
        FileCollection inputFiles = TestFiles.fixed(new File("files"))

        buildFile << """
            task myTask {
                def inputFile = file("input.txt")
                def outputFile = file("output.txt")
                inputs.file(inputFile)
                outputs.file(outputFile)
                doLast {
                    outputFile.text = inputFile.text
                }
            }
        """
        file("input.txt").text = "input"

    }

    @SuppressWarnings("GrDeprecatedAPIUsage")
    static class SimpleTask extends DefaultTask {
        @Input
        String inputString
        @InputFile
        File inputFile
        @InputDirectory
        File inputDirectory
        @InputFiles
        File inputFiles
        @OutputFile
        File outputFile
        @OutputFiles
        Set<File> outputFiles

                @InputFile inputFile
                @OutputFile outputFile

                @TaskAction copy() {
                    outputFile.parentFile.mkdirs()
                    outputFile.text = inputFile.text
                }
            }
            task customTask(type: NonCacheableTask) {
                inputFile = file("input.txt")

            error(missingNormalizationStrategyConfig { type('MyTask').property('inputFile').annotatedWith('InputFile') }, 'validation_problems', 'missing_normalization_annotation'),

                void execute() {
                    def buildDirectory = projectLayout.buildDirectory
                    inputFiles.files.each { File inputFile ->
                        def outputFile = buildDirectory.file(inputFile.name + ".out").get().asFile
                        GFileUtils.copyFile(inputFile, outputFile)
                    }
                }
            }
            allprojects {

            }
        }
    }

    def "single root file are represented as roots"() {
        given:
        withBuildCache()
        file('inputFile').text = 'inputFile'
        buildScript """
            task copy(type:Copy) {
               from 'inputFile'
               into 'destDir'
            }
        """
        when:
        succeeds("copy")

        then:

            class TaskWithNestedProperty extends DefaultTask  {
                @Nested
                Object bean
            }

            class NestedBeanWithInput {
                @InputFile
                final RegularFileProperty file

                NestedBeanWithInput(RegularFileProperty file) {
                    this.file = file
                }
            }