Comment 6 for bug 768276

Ok, so setting TARGET_TOOLS_PREFIX in build config is already supported. Actually, all variables in build config will be exported to the environment, so build config may specify any variables which may be recognized by Android build scripts. As TARGET_TOOLS_PREFIX seems to be particularly useful, I described it explicitly in
https://wiki.linaro.org/Platform/Android/LinaroAndroidBuildService?action=diff&rev2=25&rev1=24

Here's sample build: https://android-build.linaro.org/builds/~pfalcon/panda-gcc4.4.0/