[DRE-maint] Bug#818259: git usage in gemspec

[Matthias Klose]

Package: src:ruby-fog-atmos
Version: 0.1.0-2
Severity: serious
Tags: sid stretch
Justification: Breaks rdeps when binary-rebuilt

When rebuiling ruby-fog-atmos in unstable, the .gemspec is missing in
the built binaries. This causes rdeps to fail to resolve their
dependencies.

It's unclear how this package ever managed to get a .gemspec into
the binary.

see
https://launchpadlibrarian.net/216782808/buildlog_ubuntu-wily-amd64.ruby-fog-atmos_0.1.0-2build1_BUILDING.txt.gz