CMake Error at BadTargetTypeInterface.cmake:[0-9]+ \(add_custom_target\):
  Error evaluating generator expression:

    \$<TARGET_FILE:iface>

  Target "iface" is not an executable or library.
Call Stack \(most recent call first\):
  CMakeLists.txt:[0-9]+ \(include\)
+
CMake Error at BadTargetTypeInterface.cmake:[0-9]+ \(add_custom_target\):
  Error evaluating generator expression:

    \$<TARGET_SONAME_FILE:iface>

  Target "iface" is not an executable or library.
Call Stack \(most recent call first\):
  CMakeLists.txt:[0-9]+ \(include\)
+
CMake Error at BadTargetTypeInterface.cmake:[0-9]+ \(add_custom_target\):
  Error evaluating generator expression:

    \$<TARGET_LINKER_FILE:iface>

  Target "iface" is not an executable or library.
Call Stack \(most recent call first\):
  CMakeLists.txt:[0-9]+ \(include\)