Intermediate build step failure, running git across NFS mounts or up in parent non-git directories

[jkordani]

[1233/1233] Generating bin/arducopter_with_bl.hex
githash md5 a161451f19aabdb06da96d2dbe49a116
Created bin/arducopter.abin

fatal: not a git repository (or any parent up to mount point /mnt)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).

Waf: Leaving directory `/mnt/volume_nyc3_01/custom/base/tmp/copter:CubeOrangePlus:830e2c2fef9c08e7a1faff057b3c207e2253cf84:f9a0f557200efd101ce672f37ffb8e6c/CubeOrangePlus'

BUILD SUMMARY
Build directory: /mnt/volume_nyc3_01/custom/base/tmp/copter:CubeOrangePlus:830e2c2fef9c08e7a1faff057b3c207e2253cf84:f9a0f557200efd101ce672f37ffb8e6c/CubeOrangePlus

https://custom.ardupilot.org/builds/copter:CubeOrangePlus:830e2c2fef9c08e7a1faff057b3c207e2253cf84:f9a0f557200efd101ce672f37ffb8e6c/