oraios/serena · error · ValueError

Unsupported platform for Kotlin LSP {version}: {platform_id.

Error message

Unsupported platform for Kotlin LSP {version}: {platform_id.value}

What it means

Raised by `_create_artifact` for Kotlin LSP versions at or above KOTLIN_SERVER_PACKAGING_MIN_VERSION when the current platform id has no entry in KOTLIN_SERVER_ARTIFACT_BY_PLATFORM. Newer Kotlin server releases ship per-platform artifacts, so Serena can only build a download for platforms in its verified matrix; anything else is rejected rather than guessing a URL.

Source

Thrown at src/solidlsp/language_servers/kotlin_language_server.py:141

        def _create_artifact(cls, version: str, platform_id: PlatformId) -> KotlinLSPArtifact:
            """Build download and launcher metadata for one Kotlin LSP release.

            JetBrains has three publishing layouts: legacy ZIPs before 262.4739.0,
            modern platform archives under ``/kotlin-lsp`` through 262.7569.0,
            and modern archives under ``/language-server/kotlin-server`` from
            262.8190.0 onward. Serena verifies the frozen initial and current default
            releases; arbitrary user-selected versions are unverified by design.
            """
            try:
                version_parts = tuple(int(part) for part in version.split("."))
            except ValueError as exc:
                raise ValueError(f"Kotlin LSP version must contain only dot-separated integers: {version!r}") from exc

            verified = version in {INITIAL_KOTLIN_LSP_VERSION, DEFAULT_KOTLIN_LSP_VERSION}
            if version_parts >= KOTLIN_SERVER_PACKAGING_MIN_VERSION:
                artifact_config = KOTLIN_SERVER_ARTIFACT_BY_PLATFORM.get(platform_id.value)
                if artifact_config is None:
                    raise ValueError(f"Unsupported platform for Kotlin LSP {version}: {platform_id.value}")

                asset_suffix, archive_type, launcher_parts = artifact_config
                asset_name = f"kotlin-server-{version}{asset_suffix}"
                cdn_path = "language-server/kotlin-server" if version_parts >= KOTLIN_SERVER_CDN_PATH_MIN_VERSION else "kotlin-lsp"
                return KotlinLSPArtifact(
                    dependency=DownloadedDependency(
                        url=f"https://download-cdn.jetbrains.com/{cdn_path}/{version}/{asset_name}",
                        archive_type=archive_type,
                        allowed_hosts=KOTLIN_LSP_ALLOWED_HOSTS,
                        verified=verified,
                    ),
                    launcher_parts=tuple(part.format(version=version) for part in launcher_parts),
                )

            kotlin_suffix = LEGACY_PLATFORM_KOTLIN_SUFFIX.get(platform_id.value)
            if kotlin_suffix is None:
                raise ValueError(f"Unsupported platform for Kotlin LSP {version}: {platform_id.value}")

View on GitHub (pinned to 7fcbca7e62)

Solutions

1. Run on a supported platform covered by KOTLIN_SERVER_ARTIFACT_BY_PLATFORM (typical linux/windows/macos x86_64 or aarch64)
2. Pin an older Kotlin LSP version below KOTLIN_SERVER_PACKAGING_MIN_VERSION that has no per-platform split, if compatible
3. Check KOTLIN_SERVER_ARTIFACT_BY_PLATFORM in kotlin_language_server.py for supported platform keys and how your OS is detected
4. Upgrade Serena in case a platform mapping was added in a newer release

Example fix

// before: modern version on unsupported platform
_create_artifact("241.18034.62", platform_id=PlatformId.FREEBSD)
// after: legacy layout version that skips the per-platform map
_create_artifact("223.8617.171", platform_id=PlatformId.FREEBSD)

from solidlsp.language_servers.kotlin_language_server import KOTLIN_SERVER_ARTIFACT_BY_PLATFORM
if platform_id.value not in KOTLIN_SERVER_ARTIFACT_BY_PLATFORM:
    raise SystemExit(f"Kotlin LSP (modern versions) not supported on {platform_id.value}; run on linux/windows/macos x86_64 or aarch64")

def supports_modern_kotlin_lsp(platform_id) -> bool:
    return platform_id.value in KOTLIN_SERVER_ARTIFACT_BY_PLATFORM

try:
    setup_kotlin_lsp(version, platform_id)
except ValueError as e:
    if "Unsupported platform" in str(e):
        fallback_to = pick_legacy_compatible_version(platform_id)  # version < KOTLIN_SERVER_PACKAGING_MIN_VERSION
        setup_kotlin_lsp(fallback_to, platform_id)
    else:
        raise

When it happens

Trigger: `_create_artifact(version, platform_id)` with `version_parts >= KOTLIN_SERVER_PACKAGING_MIN_VERSION` and `KOTLIN_SERVER_ARTIFACT_BY_PLATFORM.get(platform_id.value)` returning None — i.e. an unsupported/unknown PlatformId (unusual OS or architecture) combined with a modern Kotlin LSP version.

Common situations: Running on an OS/arch outside JetBrains's release matrix (e.g. 32-bit, FreeBSD, unusual Linux musl identification); an updated Serena platform enum value missing from the artifact map; misconfigured platform override.

Related errors

• Kotlin LSP version must contain only dot-separated integers:
• This operation requires Serena JetBrains plugin version {'.'
• Unsupported platform: {system}
• Java {BSL_LS_MIN_JAVA_VERSION}+ is required for BSL Language
• Detected a Clojure executable, but it does not support '-Aal

AI-assisted analysis of oraios/serena@7fcbca7e62 (2026-08-29). Data as JSON: /api/errors/9fb3905f6fcef7d9. Report an issue: GitHub.