IVGCVSW-5181 Update FAQ to highlight Caffe problems on Ubuntu 20.04.

* Add a FAQ entry about the version of OpenCV causing build failures
  of Caffe on Ubuntu 20.04.

Signed-off-by: Colm Donelan <Colm.Donelan@arm.com>
Change-Id: Ic2b5b72c16a1b49411795acf14a35b5dae79d41b

diff --git a/docs/FAQ.md b/docs/FAQ.md
index ef39440..273ef92 100644 (file)
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -46,3 +46,7 @@ This problem has previously been reported to the boostorg GitHub project. The so
 ArmNN fails to build on Ubuntu 20.04
 ---------------------------------------------------------
 The compiler version update on Ubuntu 20.04 resulted in build errors in Flat buffers 1.10.0. Update to Flatbuffers 1.12.0 to resolve this problem. In addition when building flatbuffers specify -fPIC CXX flag to allow the libraries to be used in our shared objects. Without this the the ArmNN build can fail with libflatbuffers.a(util.cpp.o): relocation R_X86_64_PC32 against symbol `_ZN11flatbuffers9DirExistsEPKc' can not be used when making a shared object; recompile with -fPIC
+
+Caffe fails to build on Ubuntu 20.04
+---------------------------------------------------------
+The default version of OpenCV on Ubuntu 20.04 is 4.2. This appears to be incomatible with Caffe. Building results in missing definitions of "CV_LOAD_IMAGE_COLOR". When building Caffe to use with ArmNN you can disable OpenCV. In the Makefile.config uncomment "# USE_OPENCV := 0".