dune-spack/packages/dune/virtualenv_from_envvariable.patch

diff --git a/cmake/modules/DunePythonCommonMacros.cmake b/cmake/modules/DunePythonCommonMacros.cmake
index 6f8ff307..93ea3e9c 100644
--- a/cmake/modules/DunePythonCommonMacros.cmake
+++ b/cmake/modules/DunePythonCommonMacros.cmake
@@ -149,6 +149,10 @@ function(dune_python_require_virtualenv_setup)
   endif()
 endfunction()
 
+if (NOT "$ENV{DUNE_PYTHON_VIRTUALENV_PATH}" STREQUAL "")
+  set(DUNE_PYTHON_VIRTUALENV_SETUP 1)
+endif()
+
 # If requested, switch into DunePythonVirtualenv.cmake and setup the virtualenv.
 if(DUNE_PYTHON_VIRTUALENV_SETUP)
   include(DunePythonVirtualenv)
diff --git a/cmake/modules/DunePythonVirtualenv.cmake b/cmake/modules/DunePythonVirtualenv.cmake
index 8a09676f..96cb5954 100644
--- a/cmake/modules/DunePythonVirtualenv.cmake
+++ b/cmake/modules/DunePythonVirtualenv.cmake
@@ -81,6 +81,10 @@ set(DUNE_PYTHON_EXTERNAL_VIRTUALENV_FOR_ABSOLUTE_BUILDDIR ON CACHE BOOL
   "Place Python virtualenv in top-level directory \"dune-python-env\" when using an absolute build directory"
   )
 
+if (NOT "$ENV{DUNE_PYTHON_VIRTUALENV_PATH}" STREQUAL "")
+  set(DUNE_PYTHON_VIRTUALENV_PATH "$ENV{DUNE_PYTHON_VIRTUALENV_PATH}")
+endif()
+
 if(DUNE_PYTHON_VIRTUALENV_PATH STREQUAL "")
   foreach(mod ${ALL_DEPENDENCIES})
     if(IS_DIRECTORY ${${mod}_DIR}/dune-env)