#Note/Permanent #Programming/Python #Troubleshooting #ARM #Compilation
When working with [Python](https://www.python.org/) libraries on Apple Silicon Macs, compatibility issues can arise with pre-built binary packages. The [Keystone Engine](https://www.keystone-engine.org/) assembler framework is one such example that requires special handling for ARM64 architecture.
## The Keystone Import Error on Apple Silicon
After installing keystone-engine with pip:
```bash
pip install keystone-engine
```
Attempting to use it on ARM macOS results in this error:
```python
>>> import keystone
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/path/to/site-packages/keystone/__init__.py", line 4, in <module>
from .keystone import Ks, ks_version, ks_arch_supported, version_bind, debug, KsError, __version__
File "/path/to/site-packages/keystone/keystone.py", line 74, in <module>
raise ImportError("ERROR: fail to load the dynamic library.")
ImportError: ERROR: fail to load the dynamic library.
```
The solution requires compiling Keystone from source with explicit ARM64 architecture targeting.
## Compilation Solution for ARM64
### CMake Version Considerations
Homebrew installs CMake 4+ version which causes errors like:
```
CMake Error at CMakeLists.txt:4 (cmake_minimum_required):
Compatibility with CMake < 3.5 has been removed from CMake.
Update the VERSION argument <min> value. Or, use the <min>...<max> syntax
to tell CMake that the project requires at least <min> but has been updated
to work with policies introduced by <max> or earlier.
Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.
-- Configuring incomplete, errors occurred!
```
Using an older CMake version (3.15.0) from [CMake's official files](https://cmake.org/files/) resolves these issues.
### Compilation Steps
1. Clone the Keystone repository:
```bash
git clone https://github.com/keystone-engine/keystone.git
```
2. Create a modified version of the build script:
```bash
cp keystone/make-share.sh keystone/make-share-arm64.sh
chmod +x keystone/make-share-arm64.sh
```
3. Edit the script to explicitly target ARM64 architecture:
```bash
# Original CMake command line
cmake -DBUILD_LIBS_ONLY=$BUILD_LIBS_ONLY -DLLVM_BUILD_32_BITS="$LLVM_BUILD_32_BITS" -DCMAKE_OSX_ARCHITECTURES="$ARCH" -DCMAKE_BUILD_TYPE=$BUILDTYPE -DBUILD_SHARED_LIBS=ON -DLLVM_TARGETS_TO_BUILD="all" -G "Unix Makefiles" ..
# Modified line with ARM64 architecture explicitly set
/path/to/cmake-3.15.0-Darwin-x86_64/CMake.app/Contents/bin/cmake -DBUILD_LIBS_ONLY=$BUILD_LIBS_ONLY -DLLVM_BUILD_32_BITS="$LLVM_BUILD_32_BITS" -DCMAKE_OSX_ARCHITECTURES="arm64" -DCMAKE_BUILD_TYPE=$BUILDTYPE -DBUILD_SHARED_LIBS=ON -DLLVM_TARGETS_TO_BUILD="all" -DPYTHON_EXECUTABLE=/usr/bin/python3 -G "Unix Makefiles" ..
```
4. Create build directory and run the modified script:
```bash
mkdir -p keystone/build
cd keystone/build && ../make-share-arm64.sh
```
5. Verify the build by testing the kstool functionality:
```bash
keystone/build/kstool/kstool x64 "mov rax, 1; ret"
# Expected output: mov rax 1; ret = [ 48 c7 c0 01 00 00 00 c3 ]
```
## Integration with Python Environment
The final step involves copying the compiled library files to your Python package directory:
```bash
# Copy the compiled libraries to the Python package directory
cp keystone/build/llvm/lib/libkeystone.0.dylib /venv/py3.12/lib/python3.12/site-packages/keystone/
cp keystone/build/llvm/lib/libkeystone.dylib /venv/py3.12/lib/python3.12/site-packages/keystone/
```
For example, if your virtual environment is at `/Users/username/venv`, the target directory would be:
`/Users/username/venv/py3.12/lib/python3.12/site-packages/keystone/`