Ramips mt7621 buildbot not able to create image since 23/11/2017 RESOLVED

Hello, there appears to be failure with the mt7621 buildbot process which started from the 23rd November 2017 build process onwards. I've found some errors in the logs below which I have shortlisted. I'm not a developer but could this problem be related to the firmware binary?

os-image partition too big (more than 1703936 bytes)
Failed to open firmware file
make[4]: *** [/home/buildbot/slave-lede-local/ramips_mt7621/build/build_dir/target-mipsel_24kc_musl/linux-ramips_mt7621/tmp/lede-ramips-mt7621-re350-v1-squashfs-sysupgrade.bin] Error 1

Link to Phase 1 logs
Link to Buildbot Log and change list

Looks like @nbd has fixed the problem with a source fix. Today's mt7621 buildbot image process completed successful. I'm so impressed with the LEDE developers and their responsiveness - hats off.

Git commit