Error:Execution failed for task ':openFrameworksProject:createOpenFrameworksLibArmeabi-v7aDebugArm7StaticLibrary'. > A build operation failed. Static library archiver failed while archiving libopenFrameworksLib.a. See the complete log at: file:///

when opened output.txt i can see following error. please help me out. thank you in advance

openFrameworksCompiled/project/android/build/tmp/createOpenFrameworksLibArmeabi-v7aDebugArm7StaticLibrary/output.txt for all output for createOpenFrameworksLibArmeabi-v7aDebugArm7StaticLibrary.
archiving libopenFrameworksLib.a failed.
ar: Unknown command line argument ‘-rcs’. Try: ‘/home/sneha/software/android-ndk-r10e/toolchains/llvm-3.6/prebuilt/linux-x86_64/bin/ar -help’
ar: Did you mean ‘-M’?