Source builds using cryptography need libssl-dev (and assorted other
platform package names) to compile. Adding package declaration for
dpkg, rpm, and suse.
Adding constraints support to libraries is slightly more complex than
services as the libraries themselves are listed in upper-constraints.txt
which leads to errors that you can't install a specific version and a
This change adds constraints support by also adding a helper script to
edit the constraints to remove os-brick.
Finally, it also adds libxml2 and libxslt to bindep.txt for use when
building lxml that is now required by oslo.vmware.