No target roots found in build graph

[slvrtrn]

Hello. I am trying to contribute to this plugin https://github.com/scalapb/scalapb-pants and make it a little bit more IDEA friendly. Right now, it is not possible to import it in the IDEA 2020.1.3 with Pants plugin 1.15.1

If I comment out all the Scala BUILD definitions (leaving only the Python ones cause I want all the syntax highlighting there to redefine custom targets definitions for V1 & V2), I am getting the following error

No target roots found in build graph. Please make sure Pants export version >= 1.0.9

Output of ./pants export :: provides some Python targets though

▶ ./pants export ::
{
    "version": "1.1.0",
    "targets": {
        "//:scalapb_pants_plugin": {
            "targets": [
                "src/python:plugin"
            ],
            "libraries": [],
            "roots": [],
            "id": ".scalapb_pants_plugin",
            "target_type": "SOURCE",
            "is_code_gen": false,
            "is_synthetic": false,
            "pants_target_type": "target",
            "globs": {
                "globs": []
            },
            "transitive": true,
            "scope": "default",
            "is_target_root": true
        },
        "src/python:plugin": {
            "targets": [
                "3rdparty/python:pantsbuild.pants"
            ],
            "libraries": [],
            "roots": [
                {
                    "source_root": "/Users/serge/work/scalapb-pants/src/python/scalapb/pants/targets",
                    "package_prefix": "scalapb.pants.targets"
                },
                {
                    "source_root": "/Users/serge/work/scalapb-pants/src/python/scalapb/pants/tasks",
                    "package_prefix": "scalapb.pants.tasks"
                },
                {
                    "source_root": "/Users/serge/work/scalapb-pants/src/python/scalapb/pants",
                    "package_prefix": "scalapb.pants"
                }
            ],
            "id": "src.python.plugin",
            "target_type": "SOURCE",
            "is_code_gen": false,
            "is_synthetic": false,
            "pants_target_type": "python_library",
            "globs": {
                "globs": [
                    "src/python/./scalapb/pants/**/*.py"
                ]
            },
            "transitive": true,
            "scope": "default",
            "is_target_root": true,
            "python_interpreter": "CPython-3.7.3"
        }
// etc... 3rdparty modules and everything else

pants.toml that I am using now looks like

[GLOBAL]
v1 = true
v2 = false
pants_version = "1.29.0"
print_exception_stacktrace = true
enable_pantsd = false

pythonpath = ['%(buildroot)s/src/python']

backend_packages.add = [
    'pants.backend.python',
    'scalapb.pants',
]
backend_packages.remove = [
    'pants.backend.python.lint.isort',
]

[python-setup]
interpreter_constraints = [
    'CPython>=3.7',
]

[source]
root_patterns = [
    '%(buildroot)s/src/python',
    '%(buildroot)s/examples',
]

[scala]
version = 2.12

[jvm-platform]
default_platform = "java11"
platforms = """
{
  'java11': {'source': '11', 'target': '11', 'args': [] },
}
"""

if I uncomment Scala BUILD definitions back, I am getting this

FAILURE: Modulizable targets must not contain any synthetic target, but in this case the following synthetic targets depend on other non-synthetic modules:
{ScalaLibrary(.pants.d/gen/scalapb-gen/9c44cc2743fa/examples.simple.dep_proto/current:examples.simple.dep_proto), ScalaLibrary(.pants.d/gen/scalapb-gen/9c44cc2743fa/examples.simple.simple_proto/current:examples.simple.simple_proto), ScalaLibrary(.pants.d/gen/scalapb-gen/9c44cc2743fa/examples.client.client_proto/current:examples.client.client_proto), ScalaLibrary(.pants.d/gen/scalapb-gen/9c44cc2743fa/examples.grpc.service_proto/current:examples.grpc.service_proto)}
One approach that may help is to reduce the scope of the import to further avoid synthetic targets.

everything is working fine from the console though (I am unable to compile and run the example project using ./pants run examples/simple:main command)

[wisechengyi]

During import, did you select the intellij compiler option? If so, that's still experimental.

So either you can unselect that option, or if you are able to consume the twitter's stable branch: https://github.com/pantsbuild/pants/tree/1.25.x-twtr, it contains an option to warn instead of error pantsbuild/pants#9745

[slvrtrn]

@wisechengyi No, Intellij compiler option is not selected during import.

[wisechengyi]

Sorry I meant the other option:

intellij-pants-plugin/common/com/twitter/intellij/pants/PantsBundle.properties

Line 23 in 18861e0

pants.settings.text.import.deps.as.jars=Import source dependencies as jars [Experimental. Pants >= 1.23.0rc1 required]