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#  FAQ

#  Table of Contents

1. Why does Scalpel depend on JDK whereas Burp comes with its own JRE?
2. Why using Java with Jep to execute Python whereas Burp already supports Python extensions with Jython?
3. Once the .jar is loaded, no additional request shows up in the editor
4. My distribution/OS comes with an outdated python.
5. Configuring my editor for Python
6. I installed Python using the Microsoft Store and Scalpel doesn’t work.

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#  Why does Scalpel depend on JDK whereas Burp comes with its own JRE?

• Scalpel uses a project called jep to call Python from Java. jep needs a JDK to function.
• If you are curious or need more technical information about Scalpel’s implementation, read How scalpel works.

#  Why using Java with Jep to execute Python whereas Burp already supports Python extensions with Jython?

• Jython supports up to Python 2.7. Unfortunately, Python 3 is not handled at all. Python 2.7 is basically a dead language and nobody should still be using it.
• Burp’s developers released a new API for extensions and deprecated the former one. The new version only supports Java. That’s why the most appropriate choice was to reimplement a partial Python scripting support for Burp.

#  Once the .jar is loaded, no additional request shows up in the editor!

• When first installing Scalpel, the installation of all its dependencies may take a while. Look at the “Output” logs in the Burp “Extension” tab to ensure that the extension has completed.
• Examine the “Errors” logs in the Burp “Extension” tab. There should be an explicit error message with some tips to solve the problem.
• Make sure you followed the installation guidelines. In case you didn’t, remove the ~/.scalpel directory and try one more time.
• If the error message doesn’t help, please open a GitHub issue including the “Output” and “Errors” logs, and your system information (OS / Distribution version, CPU architecture, JDK and Python version and installation path, environment variables which Burp runs with, and so forth).

#  Scalpel requires python >=3.8 but my distribution is outdated and I can’t install such recent Python versions using the package manager.

• Try updating your distribution.
• If that is not possible, you must setup a separate Python >=3.8 installation and run Burp with the appropriate environment so this separate installation is used.

  💡 Tip: Use pyenv to easily install different Python versions and switch between them.

#  How can I configure my editor to recognize the Python library

• Python modules are extracted in ~/.scalpel/.extracted/python, adding this to your PYTHONPATH should do it.

• For VSCode users, Scalpel extracts a .vscode containing the correct settings in the scripts directory, so you can simply open the folder and it should work out of the box.

  • Alternatively, you can use the following settings.json:

    {
        "terminal.integrated.env.linux": {
            "PYTHONPATH": "${env:HOME}/.scalpel/extracted/python:${env:PYTHONPATH}",
            "PATH": "${env:HOME}/.scalpel/extracted/python:${env:PATH}"
        },
    
        // '~' or ${env:HOME} is not supported by this setting, it must be replaced manually.
        "python.analysis.extraPaths": ["<REPLACE_WITH_ABSOLUTE_HOME_PATH>/.extracted/python"]
    }
    

#  I installed Python using the Microsoft Store and Scalpel doesn’t work.

• The Microsoft Store Python is a sandboxed version designed for educational purposes. Many of its behaviors are incompatible with Scalpel. To use Scalpel on Windows, it is required to install Python from the official source.

#  error: command '/usr/bin/x86_64-linux-gnu-gcc' failed with exit code 1

• Some users encouter this error when the python developpement libraries are missing:

x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -fPIC -DPACKAGE=jep -DUSE_DEALLOC=1 -DJEP_NUMPY_ENABLED=0 -DVERSION=\"4.1.1\" -DPYTHON_LDLIBRARY=\"libpython3.10.so\" -I/usr/lib/jvm/java-11-openjdk-amd64/include -I/usr/lib/jvm/java-11-openjdk-amd64/include/linux -Isrc/main/c/Include -Ibuild/include -I/home/<user>/.scalpel/venvs/default/.venv/include -I/usr/include/python3.10 -c src/main/c/Jep/convert_j2p.c -o build/temp.linux-x86_64-cpython-310/src/main/c/Jep/convert_j2p.o
      In file included from src/main/c/Include/Jep.h:35,
                       from src/main/c/Jep/convert_j2p.c:28:
      src/main/c/Include/jep_platform.h:35:10: fatal error: Python.h: Aucun fichier ou dossier de ce type
         35 | #include <Python.h>
            |          ^~~~~~~~~~
      compilation terminated.
      error: command '/usr/bin/x86_64-linux-gnu-gcc' failed with exit code 1
      [end of output]

• Make sure you installed the python3-dev libraries for your python version https://stackoverflow.com/a/57698471