From e60d42211afeafa0f5a1ff16e8e577e3ed25929d Mon Sep 17 00:00:00 2001
From: Dominik Jain <dominik.jain@outlook.com>
Date: Mon, 23 Jun 2025 17:01:36 +0200
Subject: [PATCH] Update language server instantiation to always use
 SolidLanguageServer

---
 src/serena/agent.py     | 24 +++++++-----------------
 src/serena/constants.py |  6 +-----
 src/serena/mcp.py       |  5 ++---
 test/conftest.py        |  7 +------
 4 files changed, 11 insertions(+), 31 deletions(-)

diff --git a/src/serena/agent.py b/src/serena/agent.py
index 1ac3ffb..db96625 100644
--- a/src/serena/agent.py
+++ b/src/serena/agent.py
@@ -33,7 +33,6 @@ from sensai.util import logging
 from sensai.util.logging import LOG_DEFAULT_FORMAT, FallbackHandler
 from sensai.util.string import ToStringMixin, dict_string
 
-from solidlsp import SolidLanguageServer as SyncLanguageServer
 from serena import serena_version
 from serena.config import SerenaAgentContext, SerenaAgentMode
 from serena.constants import (
@@ -42,7 +41,6 @@ from serena.constants import (
     REPO_ROOT,
     SELENA_CONFIG_TEMPLATE_FILE,
     SERENA_MANAGED_DIR_NAME,
-    USE_SOLID_LSP,
 )
 from serena.dashboard import MemoryLogHandler, SerenaDashboardAPI
 from serena.prompt_factory import PromptFactory, SerenaPromptFactory
@@ -53,6 +51,7 @@ from serena.util.general import load_yaml, save_yaml
 from serena.util.inspection import determine_programming_language_composition, iter_subclasses
 from serena.util.shell import execute_shell_command
 from serena.util.thread import ExecutionResult, execute_with_timeout
+from solidlsp import SolidLanguageServer as SyncLanguageServer
 from solidlsp.ls import SolidLanguageServer
 from solidlsp.multilspy_config import Language, MultilspyConfig
 from solidlsp.multilspy_logger import MultilspyLogger
@@ -678,21 +677,12 @@ def create_ls_for_project(
     )
     ls_logger = MultilspyLogger(log_level=log_level)
     log.info(f"Creating language server instance for {project_instance.project_root}.")
-    if USE_SOLID_LSP:
-        ls = SolidLanguageServer.create(
-            multilspy_config,
-            ls_logger,
-            project_instance.project_root,
-            timeout=ls_timeout,
-        )
-        return cast(SyncLanguageServer, ls)  # TODO: Fix type
-    else:
-        return SyncLanguageServer.create(
-            multilspy_config,
-            ls_logger,
-            project_instance.project_root,
-            timeout=ls_timeout,
-        )
+    return SolidLanguageServer.create(
+        multilspy_config,
+        ls_logger,
+        project_instance.project_root,
+        timeout=ls_timeout,
+    )
 
 
 @click.command()
diff --git a/src/serena/constants.py b/src/serena/constants.py
index 6a27759..30a9518 100644
--- a/src/serena/constants.py
+++ b/src/serena/constants.py
@@ -19,8 +19,4 @@ DEFAULT_MODES = ("interactive", "editing")
 PROJECT_TEMPLATE_FILE = str(_serena_pkg_path / "resources" / "project.template.yml")
 SELENA_CONFIG_TEMPLATE_FILE = str(_serena_pkg_path / "resources" / "serena_config.template.yml")
 
-USE_SOLID_LSP = True
-"""Whether to use Solid LSP instead of multilspy for language server operations.
-Multilspy uses asyncio, which creates many problems like deadlocks and requires full process
-isolation (and even then some issues remain).
-"""
+USE_PROCESS_ISOLATION = False
diff --git a/src/serena/mcp.py b/src/serena/mcp.py
index e2a0bc9..83a2cbf 100644
--- a/src/serena/mcp.py
+++ b/src/serena/mcp.py
@@ -36,7 +36,7 @@ from serena.agent import (
     show_fatal_exception_safe,
 )
 from serena.config import RegisteredContext, SerenaAgentContext, SerenaAgentMode
-from serena.constants import DEFAULT_CONTEXT, DEFAULT_MODES, USE_SOLID_LSP
+from serena.constants import DEFAULT_CONTEXT, DEFAULT_MODES, USE_SOLID_LSP, USE_PROCESS_ISOLATION
 from serena.process_isolated_agent import (
     ProcessIsolatedDashboard,
     ProcessIsolatedSerenaAgent,
@@ -587,10 +587,9 @@ def start_mcp_server(
     project_file = project_file_arg if project_file_arg is not None else project
 
     mcp_factory: SerenaMCPFactory
-    if USE_SOLID_LSP:
+    if not USE_PROCESS_ISOLATION:
         mcp_factory = SerenaMCPFactorySingleProcess(context=context, project=project_file)
     else:
-        # using multilspy requires process isolation to prevent asyncio contamination
         mcp_factory = SerenaMCPFactoryWithProcessIsolation(context=context, project=project_file)
 
     # Use process isolation by default to prevent asyncio event loop contamination
diff --git a/test/conftest.py b/test/conftest.py
index 8e086cf..e41a53d 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -45,12 +45,7 @@ def create_ls(
         ignored_paths.extend(spec.patterns)
     config = MultilspyConfig(code_language=language, ignored_paths=ignored_paths, trace_lsp_communication=trace_lsp_communication)
     logger = MultilspyLogger(log_level=log_level)
-
-    if USE_SOLID_LSP:
-        ls = SolidLanguageServer.create(config, logger, repo_path)
-        return cast(SyncLanguageServer, ls)  # TODO: Fix type
-    else:
-        return SyncLanguageServer.create(config, logger, repo_path)
+    return SolidLanguageServer.create(config, logger, repo_path)
 
 
 def create_default_ls(language: Language) -> SyncLanguageServer: