8003819 : build-infra: backslashes at end of LIB and INCLUDE in spec.gmk
Sometimes vcvars*.bat seems to generate LIB and INCLUDE variables with a backslash at the end. This breaks make in the generated spec.gmk since the backslash cancels out the next line. We either need to filter away any trailing backslash or add newlines between these export lines in spec.gmk.in.
Reported by Phil Race on the build-infra-dev.
While working on JDK-8003414 on Kumar's system, I hit this problem too. With a repro case, fixing it was easy.
The cause in this case was LIB and INCLUDE already being set in the environment and SetEnv.cmd from the sdk just adding to it.