Add special function to look for a virtualenv Python

CMakeLists.txt

@@ -119,14 +119,9 @@ option (USE_PYTHON2
 # Decide on Python version before setting up googletest
 # Otherwise might use wrong version
 if (BUILD_PYTHON_BINDINGS)
-  # We currently use FindPythonInterp even though it is deprecated since 3.12
-  # This is because the scikit-build files still use this version and it will
-  # not interact well with the latest Python finding cmake modules
-  # https://cmake.org/cmake/help/v3.12/module/FindPython.html
-  # in the future, we can switch to FindPython3 once it has become more standard
-  # i.e. when the following issue is resolved:
-  # https://github.com/scikit-build/scikit-build/issues/506
-  find_package(PythonInterp 3.5 REQUIRED)
+  # Check for a virtualenv python first
+  find_package(PythonVirtualEnv)
+  find_package(Python 3.9 REQUIRED COMPONENTS Interpreter Development)
 endif()
 
 if (BUILD_BITWUZLA OR BUILD_CVC5 OR BUILD_MSAT OR BUILD_YICES2 OR BUILD_Z3)

cmake/FindPythonVirtualEnv.cmake

@@ -0,0 +1,56 @@
+# File: FindPythonVirtualEnv.cmake
+# Purpose: Detect and prefer Python from a virtual environment
+
+# Use include guard to prevent multiple inclusions
+include_guard(GLOBAL)
+
+# Function to detect and set Python from virtual environment
+function(find_python_in_virtualenv)
+    # Debugging: Print initial environment information
+    message(STATUS "Detecting Python Virtual Environment...")
+
+    # List to store potential Python paths
+    set(VENV_PATHS)
+
+    # 1. Standard virtualenv/venv path
+    if(DEFINED ENV{VIRTUAL_ENV})
+        list(APPEND VENV_PATHS "$ENV{VIRTUAL_ENV}/bin/python")
+        message(STATUS "Detected VIRTUAL_ENV: $ENV{VIRTUAL_ENV}")
+    endif()
+
+    # 2. Conda environment path
+    if(DEFINED ENV{CONDA_PREFIX})
+        list(APPEND VENV_PATHS "$ENV{CONDA_PREFIX}/bin/python")
+        message(STATUS "Detected CONDA_PREFIX: $ENV{CONDA_PREFIX}")
+    endif()
+
+    # Iterate through potential paths to find a valid Python interpreter
+    foreach(POTENTIAL_PYTHON IN LISTS VENV_PATHS)
+        if(EXISTS "${POTENTIAL_PYTHON}")
+            # Verify Python version
+            execute_process(
+                COMMAND "${POTENTIAL_PYTHON}" -c "import sys; print(f'{sys.version_info.major}.{sys.version_info.minor}')"
+                OUTPUT_VARIABLE PYTHON_VERSION
+                OUTPUT_STRIP_TRAILING_WHITESPACE
+                RESULT_VARIABLE PYTHON_VERSION_RESULT
+            )
+
+            if(PYTHON_VERSION_RESULT EQUAL 0)
+                # Check if version meets minimum requirements
+                if(PYTHON_VERSION VERSION_GREATER_EQUAL "3.9")
+                    message(STATUS "Found Virtual Environment Python: ${POTENTIAL_PYTHON}")
+                    message(STATUS "Virtual Environment Python Version: ${PYTHON_VERSION}")
+
+                    # Set variables for CMake to use
+                    set(Python_EXECUTABLE "${POTENTIAL_PYTHON}" PARENT_SCOPE)
+                    set(PYTHON_EXECUTABLE "${POTENTIAL_PYTHON}" PARENT_SCOPE)
+                    return()
+                endif()
+            endif()
+        endif()
+    endforeach()
+
+    # If no suitable virtual environment Python found, log a message
+    message(STATUS "No suitable Python virtual environment found")
+endfunction()
+

python/CMakeLists.txt

@@ -1,4 +1,6 @@
 # First, ensure we have Python 3.9 or newer with all required components
+# Check for a virtualenv python first
+find_package(PythonVirtualEnv)
 find_package(Python 3.9 REQUIRED COMPONENTS Interpreter Development)
 
 # Helper function to check for required Python packages