Currently, the only criteria was based on a hex dump of an unidentified version of the build-tools for generating manifest file. In other areas of x/mobile, it can be based on the last directory in the build tools folder which is inadequate (e.g. I have an android-4.4W folder in my build-tools/ from sdk). With CL16150, the latter has become the case for testing binaryXML output, but this needs to stop.

The general premise is that updated sdk build-tools will be backwards compatible with the output of older build-tools (the degree to which is undefined, some research on this would be nice). Picking a build-tools version to emulate would then provide some minimum guarantees to reproducible tests and general longevity.

One impediment I see to this is the distribution of build-tools versions. About how long does it take before a version is no longer available through android sdk? If this is an issue, would gomobile host the build tools similar to ndk bits?

With a version of the tools selected, tests could then perform a byte-to-byte comparison as done previously if so desired.

@crawshaw