Error handling of not found shader files

[arprixar]

If Axmol cannot find the required shader, is there a way to handle the error so as to get the names of shader files?
This is happening here, and I would really like to have some kind of onError callback in which you can get an not found file:
(axmol-dev\axmol\renderer\ProgramManager.cpp)
Program* ProgramManager::loadProgram(std::string_view vsName,
std::string_view fsName,
uint32_t progType,
uint64_t progId,
VertexLayoutKind vlk)
{
assert(!vsName.empty() && !fsName.empty());

auto it = _cachedPrograms.find(progId);
if (it != _cachedPrograms.end())
    return it->second;

auto fileUtils  = FileUtils::getInstance();
auto vertFile   = fileUtils->fullPathForFilename(vsName);
auto fragFile   = fileUtils->fullPathForFilename(fsName);

-> auto vertSource = fileUtils->getDataFromFile(vertFile);
-> auto fragSource = fileUtils->getDataFromFile(fragFile);
-> auto program = axdrv->createProgram(std::move(vertSource), std::move(fragSource));