If set, the batch errorlevel result that will be interpreted as an unstable build result. If the final errorlevel matches the value, the build results will be set to unstable and next steps will be continued. Supported values match the widest errorlevel range for Windows like systems. In Windows NT4 and beyond the ERRORLEVEL is stored as a four byte, signed integer, yielding maximum and minimum values of 2147483647 and -2147483648, respectively. Older versions of Windows use 2 bytes. DOS like systems use single byte, yielding errorlevels between 0-255. The value 0 is ignored and does not make the build unstable to keep the default behaviour consistent.