FindPython: Extend virtual environment handling by considering conda

- Add functionality to recognize and use CONDA_PREFIX environment variable
- Add tests for conda virtual environments
- Fixes: #20111

4 files changed, 75 insertions, 0 deletions

diff --git a/Tests/FindPython/VirtualEnvConda/CMakeLists.txt b/Tests/FindPython/VirtualEnvConda/CMakeLists.txt
new file mode 100644
index 0000000..565095a
--- /dev/null
+++ b/Tests/FindPython/VirtualEnvConda/CMakeLists.txt
@@ -0,0 +1,46 @@
+cmake_minimum_required(VERSION 3.1)
+
+project(TestVirtualEnvConda LANGUAGES NONE)
+
+include(CTest)
+
+find_program(CONDA_EXECUTABLE conda)
+if (CONDA_EXECUTABLE EQUAL NOTFOUND)
+  message (FATAL_ERROR "Fail to found Conda")
+endif()
+
+set (Python3_VIRTUAL_ENV "${CMAKE_CURRENT_BINARY_DIR}/condaenv")
+
+execute_process (COMMAND "${CONDA_EXECUTABLE}" create --no-default-packages --prefix "${Python3_VIRTUAL_ENV}" --yes python=3
+                 RESULT_VARIABLE result
+                 OUTPUT_VARIABLE outputs
+                 ERROR_VARIABLE outputs)
+if (result)
+  message (FATAL_ERROR "Fail to create virtual environment: ${outputs}")
+endif()
+
+add_test(NAME FindPython3.VirtualEnvDefaultConda
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           --unset=VIRTUAL_ENV
+                                           "CONDA_PREFIX=${Python3_VIRTUAL_ENV}"
+                 "${CMAKE_COMMAND}" "-DPYTHON3_VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvDefault.cmake")
+
+add_test(NAME FindPython3.VirtualEnvOnlyConda
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           --unset=VIRTUAL_ENV
+                                           "CONDA_PREFIX=${Python3_VIRTUAL_ENV}"
+                 "${CMAKE_COMMAND}" "-DPYTHON3_VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvOnly.cmake")
+add_test(NAME FindPython3.UnsetVirtualEnvOnlyConda
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           --unset=CONDA_PREFIX
+                                           --unset=VIRTUAL_ENV
+                 "${CMAKE_COMMAND}" -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvOnly.cmake")
+
+add_test(NAME FindPython3.VirtualEnvStandardConda
+         COMMAND "${CMAKE_COMMAND}" -E env --unset=PYTHONHOME
+                                           --unset=VIRTUAL_ENV
+                                           "CONDA_PREFIX=${Python3_VIRTUAL_ENV}"
+                 "${CMAKE_COMMAND}" "-DPYTHON3_VIRTUAL_ENV=${Python3_VIRTUAL_ENV}"
+                 -P "${CMAKE_CURRENT_LIST_DIR}/VirtualEnvStandard.cmake")
diff --git a/Tests/FindPython/VirtualEnvConda/VirtualEnvDefault.cmake b/Tests/FindPython/VirtualEnvConda/VirtualEnvDefault.cmake
new file mode 100644
index 0000000..020ecac
--- /dev/null
+++ b/Tests/FindPython/VirtualEnvConda/VirtualEnvDefault.cmake
@@ -0,0 +1,6 @@
+
+find_package (Python3 REQUIRED)
+
+if (NOT Python3_EXECUTABLE MATCHES "^${PYTHON3_VIRTUAL_ENV}/.+")
+  message (FATAL_ERROR "Fail to use virtual environment")
+endif()
diff --git a/Tests/FindPython/VirtualEnvConda/VirtualEnvOnly.cmake b/Tests/FindPython/VirtualEnvConda/VirtualEnvOnly.cmake
new file mode 100644
index 0000000..29a4924
--- /dev/null
+++ b/Tests/FindPython/VirtualEnvConda/VirtualEnvOnly.cmake
@@ -0,0 +1,16 @@
+
+#
+# Virtual environment is defined for python3
+# Trying to find a python2 using only virtual environment
+# It is expecting to fail if a virtual environment is active and to success otherwise.
+#
+set (Python2_FIND_VIRTUALENV ONLY)
+find_package (Python2 QUIET)
+
+if (PYTHON3_VIRTUAL_ENV AND Python2_FOUND)
+  message (FATAL_ERROR "Python2 unexpectedly found.")
+endif()
+
+if (NOT PYTHON3_VIRTUAL_ENV AND NOT Python2_FOUND)
+  message (FATAL_ERROR "Fail to find Python2.")
+endif()
diff --git a/Tests/FindPython/VirtualEnvConda/VirtualEnvStandard.cmake b/Tests/FindPython/VirtualEnvConda/VirtualEnvStandard.cmake
new file mode 100644
index 0000000..89f27d8
--- /dev/null
+++ b/Tests/FindPython/VirtualEnvConda/VirtualEnvStandard.cmake
@@ -0,0 +1,7 @@
+
+set (Python3_FIND_VIRTUALENV STANDARD)
+find_package (Python3 REQUIRED)
+
+if (Python3_EXECUTABLE MATCHES "^${PYTHON3_VIRTUAL_ENV}/.+")
+  message (FATAL_ERROR "Python3 virtual env unexpectedly found.")
+endif()