Merge branch 'i200' into 'main'

CMake: Check presence of Py packages

Closes #200

See merge request !680

cmake/BornAgain/multipython/PyDependences.cmake

@@ -63,8 +63,21 @@ function(find_multipython_dependences main_python_version)
     endforeach()
 
     if(BORNAGAIN_PYTHON_PACKAGE_VERSIONS)
+
+        # check presence of some Python modules
+        foreach(pkg build setuptools wheel)
+            message(STATUS "Searching Python package ${pkg}")
+            execute_process(
+                COMMAND ${Python3_EXECUTABLE} ${CMAKE_SOURCE_DIR}/cmake/tests/find_pkg.py ${pkg}
+                RESULT_VARIABLE PKG_FOUND)
+            if(NOT PKG_FOUND EQUAL 0)
+                message(FATAL_ERROR "Python package ${pkg} not found")
+            endif()
+        endforeach()
+
         # add the required build directories for the Python packages
         set_python_package_dirs("${BORNAGAIN_PYTHON_PACKAGE_VERSIONS}")
+
     endif(BORNAGAIN_PYTHON_PACKAGE_VERSIONS)
 
     # A member is included to build the _main_ version

cmake/tests/find_pkg.py

+#!/usr/bin/env python3
+
+# A BornAgain auxiliary script.
+# License: Public Domain.
+
+# Checks whether a given Python3 module is installed.
+#
+# Takes module name as argument.
+# Returns 0 if module can be imported. Otherwise returns 1.
+
+import sys
+pkg = sys.argv[1]
+try:
+    __import__(pkg)
+except:
+    print("     find_pkg.py: package", pkg, "not found")
+    sys.exit(1)
+
+print("     find_pkg.py: package", pkg, "found")
+sys.exit(0)