Apparently a separator fix for latest version (2.11.1) broke how paths are built, and this leads to failed builds on Linux slaves.

2.10:
[android] Ensuring platform(s) are installed: [android-8, android-19]
$ /home/jenkins/android-sdk-linux/tools/android list target

2.11.1:
[android] Ensuring platform(s) are installed: [android-8, android-19]
$ /home/jenkins/android-sdk-linux\tools\android list target
FATAL: Cannot run program "/home/jenkins/android-sdk-linux\tools\android": error=2, No such file or directory
java.io.IOException: Cannot run program "/home/jenkins/android-sdk-linux\tools\android": error=2, No such file or directory