Building with --OpNav enabled?

[scout-andrew]

Howdy BSK Team, have you been testing out the --opNav flag on Linux systems? With my current setup (a clean Ubuntu 18.04 LTS machine), I get a CMake error if I set that flag to True (see the code snippet below, with some sections omitted for clarity). It seems like CMake isn't finding the version of OpenCV conan provides - have you seen this issue before, and do you have suggestions for a workaround?

~/basilisk$  python3 conanfile.py --opNav True --vizInterface True --clean

python -m pip install --upgrade pip
Requirement already satisfied: pip in ./.venv/lib/python3.7/site-packages (23.0)

Configuring: use libstdc++11 by default
Checking conan configuration: Done
Auto-Generating Draft Modules...  Done
Running this conan command:
python -m conans.conan install . --build=missing -s build_type=Release -if dist3/conan -o opNav=True -o vizInterface=True -o buildProject=True -o clean=True
Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++11
compiler.version=7
os=Linux
os_build=Linux
[options]
buildProject=True
clean=True
opNav=True
vizInterface=True
[build_requires]
[env]
[conf]
tools.system.package_manager:mode=install

[...]

Installing (downloading, building) binaries...
[...]
opencv/4.1.2: Already installed!
[...]

CMake Error at cmake/usingOpenCV.cmake:1 (find_package):
  By not providing "Findopencv.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "opencv", but
  CMake did not find one.

  Could not find a package configuration file provided by "opencv" with any
  of the following names:

    opencvConfig.cmake
    opencv-config.cmake

  Add the installation prefix of "opencv" to CMAKE_PREFIX_PATH or set
  "opencv_DIR" to a directory containing one of the above files.  If "opencv"
  provides a separate development package or SDK, be sure it has been
  installed.
Call Stack (most recent call first):
  simulation/sensors/camera/Custom.cmake:1 (include)
  CMakeLists.txt:336 (include)
  CMakeLists.txt:565 (generate_package_targets)


-- Configuring incomplete, errors occurred!
See also "/home/andrew/basilisk/dist3/CMakeFiles/CMakeOutput.log".
ERROR: conanfile.py (Basilisk/2.1.7b0): Error in build() method, line 265
        cmake.configure()
        ConanException: Error 1 while executing cd '/home/andrew/basilisk/dist3' && cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE="Release" -DCONAN_IN_LOCAL_CACHE="OFF" -DCONAN_COMPILER="gcc" -DCONAN_COMPILER_VERSION="7" -DCONAN_CXX_FLAGS="-m64" -DCONAN_SHARED_LINKER_FLAGS="-m64" -DCONAN_C_FLAGS="-m64" -DCMAKE_CXX_FLAGS="-m64" -DCMAKE_SHARED_LINKER_FLAGS="-m64" -DCMAKE_C_FLAGS="-m64" -DCONAN_LIBCXX="libstdc++11" -DCMAKE_INSTALL_PREFIX="/home/andrew/basilisk/package" -DCMAKE_INSTALL_BINDIR="bin" -DCMAKE_INSTALL_SBINDIR="bin" -DCMAKE_INSTALL_LIBEXECDIR="bin" -DCMAKE_INSTALL_LIBDIR="lib" -DCMAKE_INSTALL_INCLUDEDIR="include" -DCMAKE_INSTALL_OLDINCLUDEDIR="include" -DCMAKE_INSTALL_DATAROOTDIR="share" -DCMAKE_PREFIX_PATH="/home/andrew/basilisk/dist3/conan" -DCMAKE_MODULE_PATH="/home/andrew/basilisk/dist3/conan" -DCMAKE_EXPORT_NO_PACKAGE_REGISTRY="ON" -DCONAN_EXPORTED="1" -DBUILD_OPNAV="True" -DBUILD_VIZINTERFACE="True" -DEXTERNAL_MODULES_PATH="" -DPYTHON_VERSION="3.7" -Wno-dev '/home/andrew/basilisk/src'

[scout-andrew]

Update, I think this is actually a case sensitivity issue. I did the following to resolve it:

1. Deleted the opencv directory inside ~/.conan/data to force conan to re-download OpenCV.
2. Ran python conanfile.py --opNav True, noted that OpenCV was re-downloaded+compiled, which included a file named OpenCVConfig.cmake. The build still failed, however, until...
3. I noted that opencvConfig.cmake is extremely close to OpenCVConfig.cmake. Changing src/cmake/usingOpenCV.cmake to look for OpenCV instead of opencv, including changing opencv_FOUND to OpenCV_FOUND builds just fine.

On MacOS and Windows, I think this may not be an issue - calls to the OS file manager on those platforms will treat opencvConfig.cmake and OpenCVConfig.cmake identically. This is generally not true on Linux, hence the original issue.

[patkenneally]

Nice find @scout-andrew . This is likely the case. The CI currently doesn't build the opnav modules. The aim is for this to change soon (a few weeks to a month or so). Until then, if you think you have a fix I encourage you create a bug issue ticket and make a PR against it.

[schaubh]

@scout-andrew , Thanks for sharing this insight. As Pat says, we currently can't build on CI with opNav turned on, work in progress. If I create a branch with this fix, would you be able to pull and test it for us? Or, if you can make a branch with a PR on this fix, I'm glad to pull and test/review.

[scout-andrew]

@patkenneally and @schaubh, thanks for the discussions! I've opened Issue #185 and PR #189 to resolve this issue - should be a quick and easy fix.