[debug] Replace mojo run JIT execution with AOT compilation and debugging of produced executable

[rolfmorel]

Moves debug execution from in-process with the compilation (i.e. mojo run making use of ORC JIT) to AOT (i.e. mojo build exe.mojo; ./exe), with LLDB attached to a process running the produced executable by itself.

This means crashes in user code will no longer be confused with compilation errors, a model that mojo run will soon adopt as well.

Also enables file debugging for wheel-installed Mojo SDKs.

Summary of changes:

• Add buildMojoFile: runs mojo build --no-optimization --debug-level full into a uniquely-named, mode-700 temp directory (created via
  mkdtemp), ad-hoc codesigns with get-task-allow on macOS (required
  for LLDB to debug a binary it launches), and returns a typed
  BuildResult. Files inside the directory are not accessible to other
  users, preventing insecure temp-file races (CWE-377/378).
• MojoDebugConfigurationResolver: replace the mojo run-as-program
  block with a withProgress-wrapped build step; on success set
  program to the binary and preserve user run-args; on failure show
  an actionable error and abort.
• MojoCudaGdbDebugConfigurationResolver: same for the cuda-gdb path.
• MojoDebugManager: add onDidTerminateDebugSession listener to
  remove the temp directory after each session.
• Remove the supportsFileDebug guard from MojoDebugConfigurationResolver.
• Add MODULAR_MOJO_MAX_LLDB_PLUGIN_PATH and
  MODULAR_MOJO_MAX_LLDB_VISUALIZERS_PATH to SDK.getProcessEnv(): the
  wheel's lldb-dap is a Python wrapper that reads these at startup to
  bootstrap the real lldb-dap binary; without them it crashes with a
  KeyError before the debug session can start.
• Downgrade the LLDB Python scripting unavailability log from ERROR
  (with full Node.js stack trace) to a single INFO line; this is a
  known SDK limitation, not an extension error.

Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[rolfmorel]

I have read the CLA Document and I hereby sign the CLA

[Copilot]

Pull request overview

This PR updates the Mojo VS Code extension’s debugging flow to compile mojoFile configurations ahead-of-time (AOT) into a temporary executable and then debug that executable, instead of launching mojo run (JIT) under the debugger. It also improves compatibility with wheel-installed SDKs by setting additional environment variables for the SDK-provided lldb-dap wrapper.

Changes:

• Added an AOT build step (mojo build --no-optimization --debug-level full) that produces a uniquely-named temp executable for debugging.
• Updated both mojo-lldb and mojo-cuda-gdb configuration resolvers to build first, then set program to the produced binary and preserve user run-args.
• Adjusted SDK environment / logging: added MODULAR_MOJO_MAX_LLDB_* env vars and downgraded missing LLDB Python scripting support logging to INFO.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
extension/pyenv.ts	Adds MODULAR_MOJO_MAX_LLDB_* env vars for wheel lldb-dap wrapper; reduces LLDB Python scripting failure log severity/noise.
extension/debug/debug.ts	Implements AOT build-to-temp-binary for debugging; adds cleanup on session termination; updates resolvers to use built executable.

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Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.