Bug#795288: libsigc++-2.0: was built with g++-4.9 on arm64

[Edmund Grimley Evans]

Source: libsigc++-2.0
Version: 2.4.1-2

Looking at the build logs at
https://buildd.debian.org/status/package.php?p=libsigc%2B%2B-2.0&suite=sid
I note that on arm64 this package was built with build-essential_11.7
and g++-4.9, unlike on the other architectures, which used g++-5. Is
this deliberate, or an accident resulting from some kind of lagginess?
If it's the latter, is there an easy way of detecting which other
packages might be affected?

(This isn't really a bug in the source package, but I can see that
this package is being actively maintained so thought this would be a
good way to contact someone who can get this fixed, if it is a
problem. I've already written to arm64 at buildd.debian.org about a
similar possible problem with cairomm. If this is all being
automatically monitored and will be fixed in due course, then sorry
for the noise.)