Any command line application return code as exit codes that notify the host environment the final status of the instruction. VS command line: devenv.com return number of codes. Although there is no (or I can't find any) such list or post regarding this. Is there any documentation? If not, anyone from VS team can document this here?
%errorlevel% (cmd.exe) or $LASTEXITCODE (Powershell) will be set to 0 on success, any other value suggests a failure for msbuild.exe or devenv.exe.