What causes "Cannot find Python source for {name}. Try gradle assemblePyPackage?" in NationalSecurityAgency/ghidra?

Run the Gradle task: './gradlew assemblePyPackage' (or ':Debugger-jpda:assemblePyPackage') to generate the pypkg/src directory.

NationalSecurityAgency/ghidra · error · Exception

Cannot find Python source for {name}. Try gradle assemblePyP

Error message

Cannot find Python source for {name}. Try gradle assemblePyPackage?

What it means

Raised by ghidra_module_pypath() in gmodutils.py when neither '<MODULE_HOME>/pypkg/src' (installed layout) nor '<MODULE_HOME>/build/pypkg/src' (dev/build layout) exists as a directory. This helper locates the Python source package for a Ghidra module so launchers can set PYTHONPATH; failure means the module's Python package was never built or installed.

Source

Thrown at Ghidra/Debug/Debugger-rmi-trace/data/support/gmodutils.py:43

that minimal logic is required to get it loaded.

This file CANNOT be assumed to be available on a remote target. For
that, consider ghidratrace.setuputils.
"""
import os
from typing import Optional


def ghidra_module_pypath(name: Optional[str]=None) -> str:
    mod_home_name = 'MODULE_HOME' if name is None else f'MODULE_{name.replace("-","_")}_HOME'
    mod_home = os.getenv(mod_home_name)
    installed = f'{mod_home}/pypkg/src'
    if os.path.isdir(installed):
        return installed
    dev = f'{mod_home}/build/pypkg/src'
    if os.path.isdir(dev):
        return dev
    raise Exception(
        f"Cannot find Python source for {name}. Try gradle assemblePyPackage?")

View on GitHub (pinned to d5f144c24d)

Solutions

Run the Gradle task: './gradlew assemblePyPackage' (or ':Debugger-jpda:assemblePyPackage') to generate the pypkg/src directory.
Verify the MODULE_HOME (or MODULE_<NAME>_HOME) environment variable points at the correct module root containing the built pypkg.
If using a distributed Ghidra install, re-install or re-extract so the pypkg/src subtree is present under the module directory.

Example fix

# before — pypkg not built yet
# (env) MODULE_HOME=/path/to/module without pypkg/src

# after
# shell
./gradlew :Debugger-jpda:assemblePyPackage
# then re-run the launcher with MODULE_HOME set to the module root

Defensive patterns

Strategy: validation

Validate before calling

import os
mod_home = os.getenv('MODULE_HOME') or os.getenv(f'MODULE_{name.replace("-","_")}_HOME')
if not (mod_home and os.path.isdir(f'{mod_home}/pypkg/src') or os.path.isdir(f'{mod_home}/build/pypkg/src')):
    raise SystemExit('Run: ./gradlew assemblePyPackage before launching')

Try / catch

try:
    from gmodutils import ghidra_module_pypath
    pypath = ghidra_module_pypath(name)
except Exception as e:
    print('Python package missing — run gradle assemblePyPackage')
    raise

Prevention

Always run 'gradle assemblePyPackage' as part of your build before launching.
Set MODULE_HOME / MODULE_<NAME>_HOME to the correct module root in launch scripts.
Verify the pypkg/src subtree exists in distributed installs.

When it happens

Trigger: A Windows launch script imports gmodutils and calls ghidra_module_pypath('Debugger-jpda') (or similar) before the module's pypkg has been assembled. The MODULE_<NAME>_HOME environment variable points at a directory tree lacking both the installed and build pypkg/src subpaths.

Common situations: Running a launcher directly from a source checkout without first executing 'gradle assemblePyPackage'; an incomplete or partially-built installation; the MODULE_HOME/MODULE_<NAME>_HOME env var pointing at the wrong root; a fresh clone that was only built with 'gradle build' but not the py-package target.

Related errors

AI-assisted analysis of NationalSecurityAgency/ghidra@d5f144c24d (2026-08-14). Data as JSON: /api/errors/f9479517f4241a3e. Report an issue: GitHub.