Build instructions not clear

[the-lost-kite]

Hello
I have been trying to build Singularity Viewer using this repository. However, I'm facing an error on autobuild with the line
"autobuild configure -cConfiguration -AArchitecture -- -DPACKAGE=OFF"
in which I have put Architecture as 64 as following
"autobuild configure -A 64"
and I'm getting error as
autobuild configure -A 64
\Warning: no --id argument or AUTOBUILD_BUILD_ID environment variable specified;
using a value from the UTC date and time (220800810), which may not be unique
'/usr/bin/cmake' '-DCMAKE_BUILD_TYPE:STRING=RelWithDebInfo' '-DADDRESS_SIZE:STRING=64' '-DROOT_PROJECT_NAME:STRING=Singularity' '-DINSTALL_PROPRIETARY=FALSE' '-G' 'Ninja' '-DADDRESS_SIZE:STRING=64' '../indra'
-- Using PKG_CONFIG_LIBDIR=/usr/lib/x86_64-linux-gnu/pkgconfig:/usr/lib/pkgconfig:/usr/local/lib/pkgconfig:/usr/share/pkgconfig:/usr/local/share/pkgconfig
Building 'Singularity Test' Version 1.8.9.8422
-- Version: 6.2.2
-- Build type: RelWithDebInfo
-- CXX_STANDARD: 14
-- Required features: cxx_variadic_templates
-- Using the single-header code from /home/innvonix/SingularityViewer/build-linux-x86_64/_deps/nlohmann_json-src/single_include/
-- No support for FMOD Studio audio (need to set FMODSTUDIO_SDK_DIR?)
-- Building with OpenAL audio support
-- Checking for module 'gstreamer-0.10'
-- No package 'gstreamer-0.10' found
CMake Error at /usr/share/cmake-3.16/Modules/FindPkgConfig.cmake:463 (message):
A required package was not found
Call Stack (most recent call first):
/usr/share/cmake-3.16/Modules/FindPkgConfig.cmake:643 (_pkg_check_modules_internal)
cmake/GStreamer010Plugin.cmake:4 (pkg_check_modules)
plugins/gstreamer010/CMakeLists.txt:18 (include)

-- Configuring incomplete, errors occurred!
See also "/home/innvonix/SingularityViewer/build-linux-x86_64/CMakeFiles/CMakeOutput.log".
See also "/home/innvonix/SingularityViewer/build-linux-x86_64/CMakeFiles/CMakeError.log".
ERROR: default configuration returned 1
For more information: try re-running your command with --verbose or --debug