NMUs on the go
June 6, 2012
Today, as an experiment, I attempted to fix a Debian bug while on
the train to work.
I use a 3G card from Three.co.uk in my Lenovo Thinkpad x121e, and
my commute is from Southampton Central to Fleet (changing at
Winchester) - just under an hour. 3G coverage is not 100%, but tends
to be better around the major stops.
- First, I found a bug. I used udd.debian.org to browse for a
relatively simple RC bug, and found bug #674992 in actionaz. The
fix was outlined in the report already, so there was very little
- Next, I confirmed the FTBFS using cowbuilder. Unfortunately, this
required downloading roughly 120MB of dependencies - I have 1GB of
data per month, but I couldn't afford to do this every day. I was
lucky in that I was near Basingstoke at the time, so had a good HSDPA
signal to get the bulk of this. The build had failed before I reached
- In the background, I updated debian/control and debian/changelog
with the fix. I was able to set off the build, but had to suspend the
laptop until lunchtime before it could finish. Cowbuilder needed to
download only a few extra build-deps, as the vast majority were cached
from the initial run.
- On the train home, I checked over the result, signed it and
uploaded. In this instance, the built package was small enough to
upload, but I could see this being a problem with others.
- Finally, I sent the nmudiff, although that was delayed briefly by
a drop in connectivity before Southampton Airport.
Thoughts: firstly, part of me is amazed that this is possible.
Secondly, there could be a case for a local Debian mirror on my
laptop. Otherwise, an interesting experimental extension to UDD would
be "Required bandwidth" - the sum of the recursive build-dependencies
plus the upload size of the diff/binaries.